The Collaborative International Dictionary
Trimorphous
Trimorphic \Tri*mor"phic\, Trimorphous \Tri*mor"phous\, a. [Gr. ? three-formed; ? (see Tri-) + morfh` form.] Of, pertaining to, or characterized by, trimorphism; -- contrasted with monomorphic, dimorphic, and polymorphic.
Wiktionary
trimorphous
a. trimorphic; having, or relating to, three forms