/ Dictionary / Index L lumpectomy: Meaning and Definition of Find definitions for: lump•ec•to•my Pronunciation: (lum-pek'tu-mē), [key] — pl. -mies. the surgical removal of a breast cyst or tumor. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lumpectomy (Thesaurus) lump lumpen Related Content Daily Word Quiz: tenacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language