DICT.TW Dictionary Taiwan

 ad

 Ad-  As a prefix ad- assumes the forms ac-, af-, ag-, al-, an-, ap-, ar-, as-, at-, assimilating the d with the first letter of the word to which ad- is prefixed. It remains unchanged before vowels, and before d, h, j, m, v. Examples: adduce, adhere, adjacent, admit, advent, accord, affect, aggregate, allude, annex, appear, etc. It becomes ac- before qu, as in acquiesce.
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 ad
      n : a public promotion of some product or service [syn: advertisement,
           advertizement, advertising, advertizing, advert]
      adv : in the Christian era; used before dates after the supposed
            year Christ was born; "in AD 200" [syn: A.D., anno
            Domini]

 A.D.
      adv : in the Christian era; used before dates after the supposed
            year Christ was born; "in AD 200" [syn: AD, anno
            Domini]