envelope
a flat paper cover or wrapper:
Put the letter into an envelope.Not to be confused with:envelop – to wrap around; enfold; hide; enclose:
Envelop the area with high walls. Abused, Confused, & Misused Words by Mary Embree Copyright © 2007, 2013 by Mary Embree
en·ve·lope
(ĕn′və-lōp′, ŏn′-)n.1. A flat paper container, especially for a letter, usually having a gummed flap.
2. Something that envelops; a wrapping.
3. Biology An enclosing structure or cover, such as a membrane or the outer coat of a virus.
4. The bag containing the gas in a balloon or airship.
5. The set of limitations within which a technological system, especially an aircraft, can perform safely and effectively.
6. Astronomy a. A usually spherical region of interstellar matter surrounding a forming star and interacting with the star's gravitational and radiation fields.
b. The coma of a comet.
7. Mathematics A curve or surface that is tangent to every one of a family of curves or surfaces.
Idiom: push the envelope To exceed or try to exceed the existing limits of a discipline or activity.
[French enveloppe, from envelopper, to envelop, from Old French envoloper; see envelop.]
Usage Note: Some people dislike the pronunciation (ŏn′və-lōp′), arguing that it is pretentious for being pseudo-French and that it is unnecessary, since there is a perfectly acceptable Anglicized pronunciation, (ĕn′və-lōp′). But the pronunciation with (ŏn) is gaining in acceptability: in our 1992 survey, 30 percent of the Usage Panel used it exclusively, and another 9 percent used it occasionally; by 2011, 46 percent selected it as their preferred pronunciation. Both forms should be considered standard.
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.
envelope
(ˈɛnvəˌləʊp; ˈɒn-) n1. a flat covering of paper, usually rectangular in shape and with a flap that can be folded over and sealed, used to enclose a letter, etc
2. any covering or wrapper
3. (Biology) biology any enclosing structure, such as a membrane, shell, or skin
4. (Aeronautics) the bag enclosing the gas in a balloon
5. (Mathematics) maths a curve or surface that is tangent to each one of a group of curves or surfaces
6. (Electronics) electronics the sealed glass or metal housing of a valve, electric light, etc
7. (General Physics) telecomm the outer shape of a modulated wave, formed by the peaks of successive cycles of the carrier wave
8. push the envelope informal to push the boundaries of what is possible
[C18: from French enveloppe, from envelopper to wrap around; see envelop; sense 8 from aeronautics jargon, referring to graphs of aircraft performance]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
en•ve•lope
(ˈɛn vəˌloʊp, ˈɑn-)
n. 1. a flat paper container, as for a letter or thin package, usu. having a gummed flap or other means of closure.
2. something that envelops; a wrapper or surrounding cover.
3. a surrounding or enclosing part, as an integument or an outer membrane.
4. Geom. a curve or surface tangent to each member of a set of curves or surfaces.
5. the fabric structure enclosing the gasbag of an aerostat.
6. the gasbag itself.
7. the airtight glass or metal housing of a vacuum tube.
8. the technical limits within which an aircraft or electronic system may be safely operated.
Idioms: push the envelope, to stretch established limits, as in technological advance or social innovation.
[1700–10; < French
enveloppe, derivative of
envelopper to
envelop]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.