(æd)  Also add. [Abbrev. of ADDICT n.] 

    A drug addict.
 
  1938 Amer. Speech XIII. 180/1 Ad. or add., a narcotic addict, especially a needle-addict. 1951 Evening Sun (Baltimore) 27 Mar. 4/1 Depending on the type of ‘junk’ he was using and the place and method of administration, he was an ‘ad’. 1976 Amer. Speech 1973 XLVIII. 208 With the drug explosion, large hospitals have increasingly admitted more ads ‘addicts’ who have taken an OD ‘overdose’.