/ Dictionary / Index R rack rail: Meaning and Definition of Find definitions for: rack' rail" Pronunciation: [key] (in an inclined-plane or mountain-climbing railway) a rail between the running rails having cogs or teeth with which cogwheels on the locomotive engage. Random House Unabridged Dictionary, Copyright 1997, by Random House, Inc., on Infoplease. rack locomotive rack railway Related Content Daily Word Quiz: abdicate Analogy of the Day: Today?s Analogy Spelling Bee: Today?s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language