/ Dictionary / Index M mast clamp: Meaning and Definition of Find definitions for: mast' clamp" Pronunciation: [key] a pierced slab of hardwood built into the deck structure of a small ship or boat to receive the force of the mast, which is fitted tightly through it. Also calleda metal collar fitted to a thwart of a small boat to steady a mast. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mast cell mast cloth Related Content Daily Word Quiz: tactful Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language