/ Dictionary / Index B board of supervisors: Meaning and Definition of Find definitions for: board' of su'pervisors Pronunciation: [key] the governing body of a county in many U.S. states, esp. in the Midwest and the East, consisting of from 15 to 100 members elected from towns, townships, cities, or wards. Cf. board of commissioners. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. board of health board of trade 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