ratch·et / ˈrachit/ • n. a device consisting of a bar or wheel with a set of angled teeth in which a pawl, cog, or tooth engages, allowing motion in one direction only. ∎  a bar or wheel that has such a set of teeth. ∎ fig. a situation or process that is perceived to be deteriorating or changing steadily in a series of irreversible steps: the best way to reverse the ratchet of socialism.• v. (ratch·et·ed, ratch·et·ing) [tr.] operate by means of a ratchet. ∎  (ratchet something up/down) fig. cause something to rise (or fall) as a step in what is perceived as a steady and irreversible process: the Bank of Japan ratcheted up interest rates again. ∎  [intr.] make a sound like a ratchet.

ratchet (Ger. Ratsche). Rattle. Percussion instr. of indefinite pitch. A cogwheel is either revolved by means of a handle against one or several tongues of wood or metal, or twirled so that the tongues strike the cogs. Is used by Strauss in Till Eulenspiegel, Ravel in his orch. of Mussorgsky's Pictures at an Exhibition, and Walton in his Façade ballet suite No.1. But of course any instr. producing a rattling noise, such as pebbles shaken in a dried gourd, is a rattle.

pawl / pôl/ • n. a pivoted curved bar or lever whose free end engages with the teeth of a cogwheel or ratchet so that the wheel or ratchet can only turn or move one way. ∎  each of a set of short stout bars that engage with the whelps and prevent a capstan, windlass, or winch from recoiling.

ratchet XVII (rochet) — F. rochet (in OF.) blunt lance-head, (later) bobbin, spool, ratchet (wheel), corr. to or partly — It. rocchetto spool, ratchet, dim. f. Rom. *rokk-. Later assim. to ratch distaff (XVIII), which may depend upon G. ratsche.

pawl (naut.) bar to prevent a capstan, etc. from recoiling. XVII. poss. — LG., Du. pal rel. to adj. pal immobile, fixed, of unkn. orig.