/ 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: modify Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language