/ Dictionary / Index L Little Boy: Meaning and Definition of Find definitions for: Lit'tle Boy' Pronunciation: [key] the code name for the uranium-fueled atomic bomb dropped by the U.S. on Hiroshima in 1945. Cf. Fat Man. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. little bluestem little brown bat Related Content Daily Word Quiz: eccentric Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language