A pawl, click, or detent, for holding or propelling a ratchet wheel, or ratch, etc.
- A mechanism consisting of a pawl that engages the sloping teeth of a wheel or bar, permitting motion in one direction only.
- The pawl, wheel, or bar of this mechanism.
- To cause to increase or decrease by increments: "Some companies . . . may make things worse if they seek to ratchet down their medical expenses by limiting benefits for psychological or psychiatric care” ( Newsweek).
- To increase or decrease by increments.