/ Dictionary / Index G gibberellin: Meaning and Definition of Find definitions for: gib•ber•el•lin Pronunciation: (jib"u-rel'in), [key] — n. Biochem. any of a class of growth hormones occurring in fungi and plants. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: gibberellin (Thesaurus) gibberellic acid gibberish 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