/ Dictionary / Index R ratchet jack: Meaning and Definition of Find definitions for: ratch'et jack" Pronunciation: [key] a screw jack rotated by a ratchet mechanism. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ratchet effect ratchet wheel Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language