MANDIBULATE is a 11 letter word that starts with M.

1. \Man*dib"u*late\, Mandibulated \Man*dib"u*la`ted\,
   a. (Zo["o]l.)
   Provided with mandibles adapted for biting, as many insects.
   
   

2. \Man*dib"u*late\, n. (Zo["o]l.)
   An insect having mandibles.