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-.

Origin of ad-

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

ad-


prefix

to; towardsadsorb; adverb
near; next toadrenal

Word Origin for 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
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

Medicine definitions for ad-

ad-


pref.

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:adductor, acclimation, agglutinant.
Near; at:adrenal.
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