ratchet(redirected from ratchet up)
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1. a device in which a toothed rack or wheel is engaged by a pawl to permit motion in one direction only
2. the toothed rack or wheel forming part of such a device
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
A wheel, usually toothed, operating with a catch or a pawl so as to rotate in only a single direction.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.