trigonal

Rhombohedral.

Pertaining to a trigon; having the form of a trigon; triangular.

In entomology, triangular in cross-section; having three long edges; trihedral; prismatic: as, trigonal antennæ; trigonal joints.

In botany, same as trigonous.

In anatomy, noting a triangular space at the base of the bladder. See trigonum .

In anatomy, the triangular space at the base of the bladder; the trigonum.

Having three angles, or corners; triangular.

symmetrically triangular

having threefold symmetry