/ Dictionary / Index A allele: Meaning and Definition of Find definitions for: al•lele Pronunciation: (u-lēl'), [key] — n. Genetics. any of several forms of a gene, usually arising through mutation, that are responsible for hereditary variation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: allele (Thesaurus) Allegro, L'* allele frequency Related Content Daily Word Quiz: digression Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language