/ Dictionary / Index D dioon: Meaning and Definition of Find definitions for: di•o•on Pronunciation: (dī'ō-on"), [key] — n. any of several Mexican and Central American palmlike plants belonging to the genus Dioon, of the cycad family, having a crown of stiff, pinnate leaves. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: dioon (Thesaurus) Dionysus diophantine equation Related Content Daily Word Quiz: hale Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language