[ ad ]
See synonyms for ad on
  1. advertising: an ad agency.

Origin of ad

First recorded in 1795–1800; by shortening

Words that may be confused with ad

Other definitions for ad (2 of 12)

[ ad ]

  1. ad in, the advantage being scored by the server.

  1. ad out, the advantage being scored by the receiver.

Origin of ad

First recorded in 1915–20; by shortening

Other definitions for ad (3 of 12)

[ ad ]

  1. (in prescriptions) to; up to.

Origin of ad

From Latin

Other definitions for ad- (4 of 12)


  1. a prefix occurring in loanwords from Latin, where it meant “toward” and indicated direction, tendency, or addition: adjoin. Usually assimilated to the following consonant; see a-5, ac-, af-, ag-, al-, an-2, ap-1, ar-, as-, at-.

Origin of ad-

<Latin ad, ad- (preposition and prefix) to, toward, at, about; cognate with at1

Other definitions for -ad (5 of 12)


  1. a suffix occurring in loanwords from Greek denoting a group or unit comprising a certain number, sometimes of years: dyad; triad.

  2. a suffix meaning “derived from,” “related to,” “concerned with,” “associated with” (oread), introduced in loanwords from Greek (Olympiad; oread), used sporadically in imitation of Greek models, as Dunciad, after Iliad.

Origin of -ad

Greek -ad- (stem of -as ), specialization of feminine adjective-forming suffix, often used substantively

Other definitions for -ad (6 of 12)


  1. variant of -ade1: ballad.

Other definitions for -ad (7 of 12)


  1. Anatomy, Zoology. a suffix forming adverbs from nouns signifying parts of the body, denoting a direction toward that part: dextrad; dorsad; mediad.

Origin of -ad

From the Latin word ad toward, anomalously suffixed to the noun; introduced as a suffix by Scottish anatomist John Barclay (1758–1826) in 1803

Other definitions for ad. (8 of 12)


  1. adverb.

  2. advertisement.

Other definitions for a.d. (9 of 12)


  1. in the year of the Lord; since Christ was born: Charlemagne was born in a.d. 742.

Origin of a.d.

From Latin annō Dominī

usage note For a.d.

Because anno Domini means “in the year of the Lord,” its abbreviation a.d. was originally placed before rather than after a date: The Roman conquest of Britain began in a.d. 43 (or began a.d. 43). In edited writing, it is still usually placed before the date. But, by analogy with the position of b.c. “before Christ,” which always appears after a date ( Caesar was assassinated in 44 b.c. ), a.d. is also frequently found after the date in all types of writing, including historical works: The Roman emperor Claudius I lived from 10 b.c. to 54 a.d. Despite its literal meaning, a.d. is also used to designate centuries, being placed after the specified century: the second century a.d.

Other definitions for a.d. (10 of 12)


  1. before the day.

Origin of a.d.

From Latin ante diem

Other definitions for a.d. (11 of 12)


  1. after date.

  2. autograph document.

Other definitions for A.D. (12 of 12)


  1. anno Domini. : Also a.d.

  1. assistant director.

  2. athletic director.

  3. average deviation. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use ad in a sentence

  • Thus the complete scale may have consisted of the disjunct tetrachords a-d and e-a, with the tone g-a.

    The Modes of Ancient Greek Music | David Binning Monro
  • It belongs to the first epoch, which includes portions of the first and second centuries A. D.

    The Swastika | Thomas Wilson
  • You must have lived like a fighting cock here—how many years ago was it, dear old A. D.?

    Polly the Pagan | Isabel Anderson
  • He had driven up quite unexpectedly and unostentatiously, and I did not see even an A.-D.

  • The dark triangular projection in the lower half of the second drawing was seen and sketched by Huyghens, 1659 A. D.

    A Text-Book of Astronomy | George C. Comstock

British Dictionary definitions for ad (1 of 7)


/ (æd) /

  1. short for advertisement

British Dictionary definitions for ad (2 of 7)


/ (æd) /

nountennis, US and Canadian
  1. short for advantage Brit equivalent: van

British Dictionary definitions for ad (3 of 7)


the internet domain name for
  1. Andorra

British Dictionary definitions for AD (4 of 7)


abbreviation for
  1. (indicating years numbered from the supposed year of the birth of Christ) anno Domini: 70 ad Compare BC

  2. military active duty

  1. military air defence

  2. Dame of the Order of Australia

Origin of AD

(sense 4) Latin: in the year of the Lord

usage For AD

In strict usage, ad is only employed with specific years: he died in 1621 ad, but he died in the 17th century (and not the 17th century ad). Formerly the practice was to write ad preceding the date (ad 1621), and it is also strictly correct to omit in when ad is used, since this is already contained in the meaning of the Latin anno Domini (in the year of Our Lord), but this is no longer general practice. bc is used with both specific dates and indications of the period: Heraclitus was born about 540 bc; the battle took place in the 4th century bc

British Dictionary definitions for ad- (5 of 7)


  1. to; towards: adsorb; adverb

  2. near; next to: adrenal

Origin of ad-

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

British Dictionary definitions for -ad (6 of 7)


suffix forming nouns
  1. a group or unit (having so many parts or members): triad

  2. an epic poem concerning (the subject indicated by the stem): Dunciad

Origin of -ad

via Latin from Greek -ad- (plural -ades), originally forming adjectives; names of epic poems are all formed on the model of the Iliad

British Dictionary definitions for -ad (7 of 7)


suffix forming adverbs
  1. denoting direction towards a specified part in anatomical descriptions: cephalad

Origin of -ad

from Latin ad to, towards

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Cultural definitions for A.D.


An abbreviation used with a date, indicating how many years have passed since the birth of Jesus. The abbreviation may appear before the date (a.d. 1988), or it may appear after the date (1988 a.d.). It stands for anno Domini, a Latin phrase meaning “in the year of our Lord.” (Compare b.c.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.