Pronunciation: (rach'it), [key]
1. a toothed bar with which a pawl engages.
2. (not in technical use) a pawl or the like used with a ratchet or ratchet wheel.
3. a mechanism consisting of such a bar or wheel with the pawl.
4. See ratchet wheel.
5. a steady progression up or down: the upward ratchet of oil prices.
to move by degrees (often fol. by up or down): to ratchet prices up; Interest rates have been ratcheting downward.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.