/ Dictionary / Index G gluteus maximus: Meaning and Definition of Find definitions for: glu'teus max'i•mus Pronunciation: (mak'su-mus), [key] — pl. glutei max•i•mi the broad, thick, outermost muscle of the buttocks, involved in the rotation and extension of the thigh. the buttocks. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. gluteus gluteus medius Related Content Daily Word Quiz: portent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language