/ Dictionary / Index B basidium: Meaning and Definition of Find definitions for: ba•sid•i•um Pronunciation: (bu-sid'ē-um), [key] — pl. -sid•i•a a special form of sporophore, characteristic of basidiomycetous fungi, on which the sexual spores are borne, usually at the tips of slender projections. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: basidium (Thesaurus) basidiospore Basie Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language