/ Dictionary / Index H hairbrush cactus: Meaning and Definition of Find definitions for: hair'brush cac"tus Pronunciation: [key] a stout, spiny cactus, Pachycereus pecten-aboriginum, of Mexico, having white flowers and bristly fruits sometimes used locally as combs. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. hairbrush hair cell Related Content Daily Word Quiz: sequester Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language