Definitions
1.nounA pawl, click or detent for holding or propelling a ratchet wheel, or ratch, etc.
2.nounA mechanism composed of a ratchet wheel, or ratch and pawl.
3.nounA ratchet wrench.
4.noun(by extension) A procedure or regulation that goes in one direction, usually up.
5.verbTo cause to become incremented or decremented."It's time to ratchet up the intensity level here."
6.verbTo increment or decrement.