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noun (1)

ˈad

often attributive

: advertisement sense 1

newspapers ads

TV ads for new cars

: advertising

an ad agency

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abbreviation (1)

active duty

after date

airworthiness directive

Alzheimer's disease

anno Domini

—often printed in small capitals and often punctuated

assembly district

assistant director

athletic director

right ear

—used especially in audiology and in writing medical prescriptions

A/D

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prefix

variants or ac- or af- or ag- or al- or ap- or as- or at-

: to : toward

—usually ac- before c, k, or q

acculturation

and af- before f

affluent

and ag- before g

aggradation

and al- before l

alliteration

and ap- before p

apportion

and as- before s

assuasive

and at- before t

attune

and ad- before other sounds but sometimes ad- even before one of the listed consonants

adsorb

: near : adjacent to

—in this sense always in the form ad-

adrenal

-ad

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adverb suffix

: in the direction of : toward

cephalad

-ad

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Word History

Etymology

Noun (1)

by shortening

Noun (2)

by shortening

Prefix

borrowed from Latin, prefix forming verbs and verbal derivatives, marking movement toward, tendency, addition, from ad, preposition, "to, as far as, at, near, in accordance with" — more at at entry 1

Adverb suffix

borrowed from Latin ad "to, toward" — more at at entry 1

Noun suffix

borrowed from New Latin -ad-, -as, borrowed from Greek -ad-, -as, feminine noun suffix denoting descent from or connection with

First Known Use

Noun (1)

1799, in the meaning defined at sense 1

Noun (2)

1915, in the meaning defined above

Time Traveler

The first known use of ad was in 1799

See more words from the same year

Cite this Entry

Style

“Ad.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ad. Accessed 7 Dec. 2022.

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Kids Definition

1 of 2 noun

ˈad

: advertisement sense 2

ad-

2 of 2 prefix

variants or ac- or af- or ag- or al- or ap- or as- or at-

: to : toward

—usually ac- before c, k, or q and af- before f and ag- before g and al- before l and ap- before p and as- before s and at- before t and ad- before other sounds but sometimes ad- even before one of the listed consonants