[ratch.et] n [alter. of earlier rochet, fr. F, alter. of MF rocquet ratchet, bobbin, of Gmc origin; akin to OHG rocko distaff--more at rock] (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 ratchet wheel
[2]ratchet vt (1973): to cause to move by steps or degrees--usu. used with up or down "tried to ~ down the debt" ~ vi: to proceed by steps or degrees