[1] : The Collaborative International Dictionary of English v.0.48

ad- \ad-\ a latin preposition, signifying to. see at.
   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.
   1913 webster
see also:
at 

[2] : WordNet (r) 2.0

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
see also:
advertisement advertizement advertising advertizing advert a.d. 
anno domini 

[3] : WordNet (r) 2.0

a.d.
     adv : in the christian era; used before dates after the supposed
           year christ was born; "in ad 200" syn: ad, anno
           domini
see also:
ad anno domini 

[4] : Virtual Entity of Relevant Acronyms (Version 1.9, June 2002)

ad
     active directory ms, windows, ad, ds
     
     

[5] : Virtual Entity of Relevant Acronyms (Version 1.9, June 2002)

ad
     analog-to-digital d/a, "a/d"
     
     

[6] : Virtual Entity of Relevant Acronyms (Version 1.9, June 2002)

ad
     authorized distributor dec
     
     

[7] : Virtual Entity of Relevant Acronyms (Version 1.9, June 2002)

ad
     autonomous domain
     
     

[8] : The Free On-line Dictionary of Computing (27 SEP 03)

ad
     
        administrative domain
     
     
see also:
administrative domain 

[9] : The Free On-line Dictionary of Computing (27 SEP 03)

ad
     
         the country code for andorra.
     
        1999-01-26
     
     
see also:
country code 

Ad- >> A Words
Ad-, definition of term: Ad-
ad-_pag1.html