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1. or ac- or af- or ag- or al- or ap- or as- or at- Toward; to. Before c, f, g, k, l, p, q, s, and t, ad- is usually assimilated to ac-, af-, ag-, ac-, al-, ap-, ac-, as-, and at-, respectively.
2. Near; at: adrenal.
1. to; towards: adsorb; adverb.
2. near; next to: adrenal.
[from Latin: to, towards. As a prefix in words of Latin origin, ad- became ac-, af-, ag-, al-, an-, acq-, ar-, as-, and at- before c, f, g, l, n, q, r, s, and t, and became a- before gn, sc, sp, st]
1. an advertisement.
2. advertising: an ad agency.
[1835–45; by shortening]
[1925–30; by shortening]
a prefix occurring in verbs or verbal derivatives borrowed from Latin, where it meant “toward” and indicated direction, tendency, or addition: adjoin. For variants before a following consonant, see a-5, ac-, af-, ag-, al-, an-2, ap-1, ar-, as-, at-.
[< Latin ad, ad- (preposition and prefix) to, toward, at, about; c. at1]
1. a suffix occurring in loanwords from Greek denoting a group or unit comprising a certain number, sometimes of years: myriad; Olympiad; triad.
2. a suffix meaning “derived from,” “related to,” “associated with,” occurring in loanwords from Greek (dryad; oread) and in New Latin coinages on a Greek model (bromeliad; cycad).
3. a suffix used, on the model of Iliad, in the names of epics, speeches, etc., derived from proper names: Dunciad; jeremiad.
[< Greek -ad-, s. of -as]
var. of -ade1: ballad; salad.
a suffix used in anatomy to form adverbs from nouns signifying parts of the body, denoting a direction toward that part: ectad.
[< Latin ad toward, anomalously suffixed to the noun]
1. in the year of the Lord; since Christ was born: Charlemagne was born in a.d.742.
(Latin annō Dominī]
2. assembly district.
3. athletic director.
usage: The abbreviation a.d. was orig. placed before a date and is still usu. preferred in edited writing: The Roman conquest of Britain began in a.d.43 (or, sometimes, began a.d.43). The abbreviation b.c. (before Christ) is always placed after a date: Caesar was assassinated in 44 b.c. But by analogy with the position of b.c., a.d. is frequently found after the date in all types of writing: Claudius I lived from 10 b.c.to 54 a.d. This abbreviation may also designate centuries, being placed after the century specified: the second century a.d. Some writers prefer to use c.e. (Common Era) and b.c.e. (Before the Common Era) to avoid the religious overtones of a.d. and b.c.