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n. pl. ec·cen·tric·i·ties
a. The quality of being eccentric.
b. Deviation from the normal, expected, or established.
2. An example or instance of eccentric behavior.
3. Physics The distance between the center of an eccentric and its axis.
4. Mathematics The ratio of the distance of any point on a conic section from a focus to its distance from the corresponding directrix. This ratio is constant for any particular conic section.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


n, pl -ties
1. unconventional or irregular behaviour
2. (Mathematics) deviation from a circular path or orbit
3. (Astronomy) a measure of the noncircularity of an elliptical orbit, the distance between the foci divided by the length of the major axis
4. (Mathematics) geometry a number that expresses the shape of a conic section: the ratio of the distance of a point on the curve from a fixed point (the focus) to the distance of the point from a fixed line (the directrix)
5. (Mechanical Engineering) the degree of displacement of the geometric centre of a rotating part from the true centre, esp of the axis of rotation of a wheel or shaft
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˌɛk sənˈtrɪs ɪ ti, ˌɛk sɛn-)

n., pl. -ties.
1. an oddity or peculiarity, as of conduct.
2. the quality of being eccentric.
3. the amount by which something is eccentric.
4. a mathematical constant expressed as the ratio of the distance from a point on a conic to a focus and the distance from the point to the directrix.
[1545–55; < Medieval Latin]
syn: eccentricity, peculiarity, quirk, idiosyncrasy all refer to some deviation in behavior, style, or manner from what is or expected. eccentricity usu. suggests a mildly amusing but harmless characteristic or style: a whimsical eccentricity of dress. peculiarity is the most general of these words, referring to almost any perceptible oddity or departure from any norm: a peculiarity of the language. quirk often refers to a minor, unimportant kind of oddity: Her one quirk was a habit of writing long, rambling letters. Sometimes quirk has overtones of strangeness: sexual quirks. idiosyncrasy refers to a variation in behavior or manner exclusive to or characteristic of a single individual: idiosyncrasies of style that irritated editors but often delighted readers.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.




barmy on the crumpet Eccentric; a bit daft; wacko. This picturesque British expression plays on barmy ‘balmy, foolish’ and barmy ‘yeasty’—a crumpet being a breadlike muffin, here metaphorically standing for one’s head.

have a moonflaw in the brain To be a lunatic; to behave in a very bizarre or peculiar manner. A moonflaw is an abnormality or idiosyncrasy ascribed to lunar influence. This now obsolete expression appeared in Brome’s Queen and Concubine (1652):

I fear she has a moonflaw in her brains;
She chides and fights that none can look upon her.

have a screw loose To be eccentric, crotchety, or neurotic; to be irregular or amiss. As early as 1884, the phrase loose screw was used figuratively to apply to a flawed condition or state of affairs.

I can see well enough there’s a screw loose in your affairs. (Charles Dickens, The Life and Adventures of Martin Chuzzlewit, 1884)

A more recent and increasingly common figurative meaning applies have a screw loose to states of mind or mental health. This slang meaning is used in regard to whimsical, unusual behavior rather than to disturbed or sick behavior, although the phrase tends to conjure up images of “falling apart” or “breaking down.” A British variant is have a tile loose.

have bats in one’s belfry To be eccentric, bizarre, crazy, daft. The erratic flight of bats in bell towers interferes with the proper ringing and tone of the bells, just as crazy notions darting about one’s brain weaken its ability to function. The slang term batty is a derivative of this phrase, which appeared as early as 1901 in a novel of G. W. Peck:

They all thought a crazy man with bats in his belfry had got loose. (Peck’s Red-Haired Boy)

The analogy between sanity and finely tuned bells is an old one; its most famous expression is in Ophelia’s description of the “mad” Hamlet:

Now see that noble and most sovereign reason,
Like sweet bells jangled, out of tune and harsh. (III, i)

off one’s trolley Crazy, demented; in a confused or befuddled state of mind; ill-advised; senile. This expression alludes to the once-common spectacle of a motorman’s attempts to realign the contact wheel of a trolley car with the overhead wire. Since this contact wheel is also called a “trolley,” off one’s trolley may refer either to the conductor’s actions or to the fact that when the wires are “off the trolley,” the vehicle no longer receives an electric current and is, therefore, rendered inoperative.

The medium is clear off her trolley, for my father has been dead [for] three years. (Warren Davenport, Butte and Montana Beneath the X-Ray, 1908)

A similar expression is slip one’s trolley ‘to become demented.’ In the more widely used variation, off one’s rocker, rocker is most often said to refer to the curved piece of wood on which a cradle or chair rocks. But since both off one’s trolley and off one’s rocker became popular about the time streetcars were installed in major American cities, and since rocker, like trolley, also means the wheel or runner that makes contact with an overhead electricity supply, it is more likely that the rocker of the expression carries this latter meaning.

When asked if he had swallowed the liniment, he said, “Yes, I was off my rocker.” (Daily News, June 29, 1897)

queer in the attic Eccentric or feebleminded; intoxicated. In this expression, attic carries its British slang meaning of ‘the mind’; thus, this colloquialism alludes to stupidity, insanity, or drunkenness, all of which may generate bizarre behavior.

round the bend Insane, crazy. In this British expression, bend describes one’s mental faculties as being ‘out of alignment, bent, or out of kilter.’

Right round the bend … I mean … as mad as a hatter. (John I. M. Stewart, The Guardian, 1955)

Related expressions are go round the bend and be driven round the bend.

Picturesque Expressions: A Thematic Dictionary, 1st Edition. © 1980 The Gale Group, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.eccentricity - strange and unconventional behavior
strangeness, unfamiliarity - unusualness as a consequence of not being well known
oddity, oddness - eccentricity that is not easily explained
2.eccentricity - (geometry) a ratio describing the shape of a conic section; the ratio of the distance between the foci to the length of the major axis; "a circle is an ellipse with zero eccentricity"
geometry - the pure mathematics of points and lines and curves and surfaces
ratio - the relative magnitudes of two quantities (usually expressed as a quotient)
3.eccentricity - a circularity that has a different center or deviates from a circular path
circularity, disk shape - the roundness of a 2-dimensional figure
concentricity - the quality of having the same center (as circles inside one another)
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.


Collins Thesaurus of the English Language – Complete and Unabridged 2nd Edition. 2002 © HarperCollins Publishers 1995, 2002


The American Heritage® Roget's Thesaurus. Copyright © 2013, 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
شُذوذ، غَرابَةُ الأطْوار


[ˌeksənˈtrɪsɪtɪ] Nexcentricidad f
Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005


[ˌɛksɛnˈtrɪsɪti] n
(= oddness) → excentricité f
(= odd way of behaving) → bizarrerie f
Collins English/French Electronic Resource. © HarperCollins Publishers 2005


n (all senses) → Exzentrizität f
Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007


[ˌɛksənˈtrɪsɪtɪ] neccentricità f inv
Collins Italian Dictionary 1st Edition © HarperCollins Publishers 1995


(ikˈsentrik) adjective
(of a person, his behaviour etc) odd; unusual. He is growing more eccentric every day; He had an eccentric habit of collecting stray cats.
an eccentric person.
ecˈcentrically adverb
eccentricity (eksenˈtrisəti) noun
oddness of behaviour or an example of this.
Kernerman English Multilingual Dictionary © 2006-2013 K Dictionaries Ltd.
References in classic literature ?
If he had picked out the most inappropriate word in the whole dictionary to describe the lady whom I had met on the beach, "Eccentricity" would have been that word.
Eccentricity! My mother's odd way of making acquaintance with you."
At any rate, it was a harmless eccentricity, and may the god of gales, who took him away so abruptly between New Zealand and the Horn, let his soul rest in some Paradise of true seamen, where no amount of carrying on will ever dismast a ship!
Remarkable anywhere, by his personal appearance, he was still further distinguished among the rank and file of mankind by the harmless eccentricity of his character.
The Puritans looked on, and, if they smiled, were none the less inclined to pronounce the child a demon offspring, from the indescribable charm of beauty and eccentricity that shone through her little figure, and sparkled with its activity.
If to live in this style is to be eccentric, it must be confessed that there is something good in eccentricity.
The time has passed when he was an object of ridicule, and it is no longer a mark of eccentricity to defend or of perversity to extol him.
In the streets of London where beauty goes unregarded, eccentricity must pay the penalty, and it is better not to be very tall, to wear a long blue cloak, or to beat the air with your left hand.
With their sharp eye for eccentricity, they were inclined to think Mr.
When we are merely studying an eccentricity, the method of our study is but a series of allowances.
'English eccentricity,' the man looked at the hotel register, and led the lady upstairs again to the room occupied by her maid.
If he were rather inclined to be lazy, liking better the fishing he had been born for than the farming he had not, and if he had a harmless eccentricity for doing fancy work, nobody save Miss Cornelia seemed to hold it against him.