/ Dictionary / Index B board rule: Meaning and Definition of Find definitions for: board' rule" Pronunciation: [key] — Building Trades. Building Trades. a measuring device having scales for finding the cubic contents of a board without calculation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. boardroom boardsailing Related Content Daily Word Quiz: hedonist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language