/ Dictionary / Index R rattler: Meaning and Definition of Find definitions for: rat•tler Pronunciation: (rat'lur), [key] — n. a rattlesnake. a person or thing that rattles. a fast freight train. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: rattler (Thesaurus) rattlepate rattlesnake Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language