- also a- before sc, sp, st, ac- before c, k, q, af- before f, ag- before g, al- before l, an- before n, ap- before p, ar- before r, as- before s, at- before t)
1 with the sense of motion or direction to, reduction or change into, addition, adherence, increase, or intensification.
2 formed by assimilation of other prefixes (accurse; admiral; advance; affray).
Etymology: (sense 1) (through OF a-) f. L ad to: (sense 2) a- repr. various prefixes other than ad-
* * *prefix or ac- or af- or ag- or al- or ap- or as- or at-Etymology: ad- from Middle English, from Latin, from ad; ac- from Middle English, from Old French, from Latin, from ad; af- from Middle English, from Old French, from Latin, from ad; ag- from Middle English, from Middle French, from Latin, from ad; al- from Middle English, from Middle French, from Latin, from ad; ap- from Middle English, from Middle French, from Latin, from ad; as- from Middle English, from Old French, from Latin, from ad; at- from Middle English, from Old French, from Latin, from ad — more at at
attuneand ad- before other sounds
adverbialbut sometimes ad- even before one of the listed consonants
adpronominal2. : near : adjacent to — in this sense always in the form ad-
* * *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-.
* * *Informal. an advertisement: »
... the breathless, exotic coquetry of the cosmetic ads (Saturday Review).Usage Ad is the clipped form of advertisement in the United States and Canada, and is also spreading in use in Great Britain; advert is a form used less often in Great Britain.advantage (the first point won in a game of tennis after deuce).ad-,prefix.2. at; near, as in adjacent, adrenal. Also: a- before sc, sp, st; ab- before b; ac- before c, k, q; af- before f; ag- before g; al- before l; an- before n; ap- before p; ar- before r; as- before s; at- before t.╂[< Latin ad- < ad to, toward, at]ad.,advertisement.a.d.,Commerce. after date.AD (no periods),1. adenoid-degenerating (of a type of respiratory disease).2. Alzheimer's disease.A/D,analogue to digital (conversion in computers).A.D. or AD (no periods),since Christ was born; after the birth of Christ: »
Charlemagne was crowned by the Pope in 800 A.D. From A.D. 100 to A.D. 500 is 400 years.╂[for Late Latin annō Dominī in the year of our Lord]Usage A.D. might be expected to occur only with a particular year: »
1376 A.D.It has long been used, however, in the sense “after Christ,” corresponding to B.C., “before Christ”: »
the 5th century A.D.With a particular year, it often occurs before the figure: »
* * *prefix denoting motion or direction to
advance | adduce■ reduction or change into
adapt | adulterate■ addition, increase, or intensification
adjunct | adhere | admixtureOrigin:from Latin ad ‘to’; in the 16th cent. the use of ad- and its variants was extended to replace a- from a different origin such as Latin ab- (e.g., advance, from French avancer, based on late Latin abante ‘in front’)••UsageThe prefix ad- is also found assimilated in the following forms: a- before sc, sp, st; ac- before c, q; af- before f; ag- before g; al- before l; an- before n; ap- before p; ar- before r; as- before s; at- before t
* * *ad-, prefix1. repr. L. ad prep. ‘to,’ cogn. w. Teut. at, frequent in comp. with sense of motion or direction to, reduction or change into, addition, adherence, increase, or simple intensification, as ad-ventus, ad-versus, ad-ditus, ad-albātus, ad-ministrāre, ad-augēre. Before the consonants c, f, g, l, n, p, q, r, s, t, ad- was in later L. assimilated, as ac-, af-, ag-, al-, an, ap-, ac-, ar-, as-, at-; and before sc, sp, st it was reduced to a- (a-scendere, a-strictus, a-spirāre). It remained before vowels, and the consonants d, h, j, m, v. It was probably assimilated before b, in ab-breviāre, for ad-breviāre, cf. al-leviāre, attenuāre, accurtāre. In OFr. ad- was reduced to a- in all cases where its character as a prefix was recognized, even before vowels, as adōrāre, aörer, adornāre, aörner, adæstimāre, aesmier. But in the 14th c. the written forms began to be artificially refashioned after L., this being in words like alouer allouer, anoncer annoncer, atendre attendre, only an artificial spelling, but resulting, in such as aörer adorer, ajoint adjoint, in a real change of sound. In 15th c. this fashion spread to England, where the words had originally been adopted in their OFr. forms, and was here carried out far more rigorously, attacking also words that remained unchanged in Fr., or in which the pedantic form was again rejected, as a-dresser ad-dress, a-vertissement ad-vertisement, a-vouerie ad-vowry. All words subsequently formed in Fr. and adopted in Eng., or formed in Eng. on L. words, or according to L. analogies, follow L. spelling. A very recent use of ad-, unknown to L., is to employ it in contrast to ab- in pairs like ad-oral, ab-oral, situated at the mouth, and away from the mouth.2. While the refashioning of words in OFr. a- was going on in 16th c., mechanical imitation or pedantic assumption extended ad- and its variants to many words in which a- had quite a different origin, as L. ab, OFr. en (an), es, re, OE. a (ar), on, æt, etc.; as in a(d)vance Fr. avancer L. ab-anteāre, a(d)debted OFr. endetté, a(c)cloy OFr. encloyer L. inclāvāre, admerveyl OFr. esmerveiller, a(f)fray OFr. esfreyer, a(f)force OFr. esforcer L. *exfortiare, a(c)curse ME. a-curse, a(l)lay OE. a-lecȝan, a(c)know(ledge OE. on-cnawan, a(d)blast OE. onblæstan, a(d)dight OE. a-dihtan, ȝe-dihtan, a(d)miral Arab. amīr-al-. New compounds of native words with prefix a- were also falsely written ad-, as a(d)deem, a(d)doom. In most of these words the perversion went no farther than the spelling, but in some, as a(d)vance, a(d)miral, it has distorted the spoken word.
Useful english dictionary. 2012.