/ Dictionary / Index C costumer: Meaning and Definition of Find definitions for: cos•tum•er Pronunciation: (kos't-mur, -ty-&wdspcko-st'mur, -sty'-), [key] — n. a person who makes, sells, or rents costumes, as for theatrical productions. a clothes tree. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: costumer (Thesaurus) costume jewelry costumery Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language