/ Dictionary / Index T trigonal trisoctahedron: Meaning and Definition of Find definitions for: trig'onal trisoctahe'dron Pronunciation: [key] a trisoctahedron whose faces are triangles. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. trigonal trigone Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language