Main Entry: ¹ratch·et

Variant(s): also rach·et \ˈra-chət\

Function: noun

Etymology: alteration of earlier rochet, from French, alteration of Middle French rocquet ratchet, bobbin, of Germanic origin; akin to Old High German rocko distaff — more at rock

Date: 1654

1 : a mechanism that consists of a bar or wheel having inclined teeth into which a pawl drops so that motion can be imparted to the wheel or bar, governed, or prevented and that is used in a hand tool (as a wrench or screwdriver) to allow effective motion in one direction only
2 : a pawl or detent for holding or propelling a toothed wheel