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AD Definition & Meaning | Dictionary.com

ad 2 American  

[ad] / æd /

  1. advantage.

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

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

ad 3 American  

[ad] / æd /

preposition

  1. (in prescriptions) to; up to.

  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; a-, ac-, af-, ag-, al-, an-, ap-, ar-, as-, at-.

  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 .

  1. variant of -ade: ballad .

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

abbreviation

  1. adverb.

  2. advertisement.

abbreviation

  1. in the year of the Lord; since Christ was born.

    Charlemagne was born in a.d. 742.

abbreviation

  1. before the day.

abbreviation

  1. after date.

  2. autograph document.

abbreviation

  1. active duty.

  2. anno Domini. Also a.d.

  3. art director.

  4. assembly district.

  5. assistant director.

  6. athletic director.

  7. average deviation.

abbreviation

  1. anno Domini Compare BC

    70 ad

  2. military active duty

  3. military air defence

  4. Dame of the Order of Australia

"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

suffix

  1. a group or unit (having so many parts or members)

    triad

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

    Dunciad

"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

prefix

  1. to; towards

    adsorb

    adverb

  2. near; next to

    adrenal

"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

suffix

  1. denoting direction towards a specified part in anatomical descriptions

    cephalad

"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

noun

  1. short for advertisement

"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

noun

  1. Brit equivalent: van.  short for advantage

"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

abbreviation

  1. Andorra

"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

Usage

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.

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

Etymology

Origin of ad1

First recorded in 1795–1800; by shortening

Origin of ad2

First recorded in 1915–20; by shortening

Origin of ad3

From Latin

Origin of ad-4

< Latin ad, ad- (preposition and prefix) to, toward, at, about; cognate with at 1

Origin of -ad5

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

Origin of -ad7

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

Origin of a.d.9

From Latin annō Dominī

Origin of a.d.10

From Latin ante diem

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The number of ad placements isn’t set to change as part of the redesign, the company said.

From The Wall Street Journal

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Radio airplay, strong word of mouth, glossy production and a slick cover that looked like an upscale fragrance ad helped the record sell a million copies by September 1976.

From The Wall Street Journal

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The agency is focused on whether the company violated platform partners’ service agreements to enhance ad targeting, the report said.

From Barron's

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In academia, the strategy of trapping customers is sometimes called the “roach motel,” she explained, a reference to a popular television ad from the late 1970s for a cockroach trap.

From Los Angeles Times

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“Women don’t want to see your fish,” a man reads in one ad, referring to the trope of men showing off fish they’ve caught in dating-app profiles.

From The Wall Street Journal

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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.