Source : Webster's Revised Unabridged Dictionary (1913)

Bignoniaceous \Big*no`ni*a"ceous\, a. (Bot.)
   Of pertaining to, or resembling, the family of plants of
   which the trumpet flower is an example.

Source : WordNet®

bignoniaceous
     adj : of or pertaining to or characteristic of plants of the
           family Bignoniaceae