trigrammatic

CIDE DICTIONARY

trigrammatic, a. [Gr. ; + a letter.].

 Containing three letters or characters, or three sets of letters or characters.  [1913 Webster]

ROGET THESAURUS

trigrammatic

Trisection

N trisection, tripartition, trichotomy, third, third part, trifid, trisected, tripartite, trichotomous, trisulcate, Triadelphous, triangular, tricuspid, tricapsular, tridental, tridentate, tridentiferous, trifoliate, trifurcate, trigonal, trigrammic, trigrammatic, tripetalous, tripodal, tripodic, triquetral, triquetrous.