ADULTERINE is a 10 letter word that starts with A.

1. \A*dul"ter*ine\, a.[L. adulterinus, fr. adulter.]
   Proceeding from adulterous intercourse. Hence: Spurious;
   without the support of law; illegal.
   
         When any particular class of artificers or traders
         thought proper to act as a corporation without a
         charter, such were called adulterine guilds. --Adam
                                                  Smith.
   
   

2. \A*dul"ter*ine\, n.
   An illegitimate child. [R.]