Source : Webster's Revised Unabridged Dictionary (1913)

Thecodont \The"co*dont\, a. [Gr. ? a case + ?, ?, a tooth.]
   1. (Anat.) Having the teeth inserted in sockets in the
      alveoli of the jaws.

   2. (Paleon.) Of or pertaining to the thecodonts.

Thecodont \The"co*dont\, n. (Paleon.)
   One of the Thecodontia.

Source : WordNet®

thecodont
     n : presumably in the common ancestral line to dinosaurs and
         crocodiles and birds [syn: {thecodont reptile}]