/ Dictionary / Index T trainline: Meaning and Definition of Find definitions for: train•line Pronunciation: (trān'līn"), [key] — n. a pipe or hose distributing compressed air through a train for operation of the brakes. Also called train&syl;pipe. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. training wheels trainload Related Content Daily Word Quiz: crutiny Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language