Trī-mōrph'ism, n.

n. [Gr. τρι, τρίς, three, thrice, and μορφή, form.] (Crystallog.) The property of crystallizing in three forms fundamentally distinct, as with titanic acid, one of the forms of which is the mineral anatase, another rutile, another brookite, the first two being dimeric, the last one trimetric.