Main Entry: ¹cal·i·per

Pronunciation: \ˈka-lə-pər\

Function: noun

Etymology: alteration of caliber

Date: 1588

1 a : any of various measuring instruments having two usually adjustable arms, legs, or jaws used especially to measure diameter or thickness —usually used in plural <a pair of calipers> b : a device for pressing a frictional material (as a brake pad) against the sides of a rotating wheel or disc
2 : thickness especially of paper, cardboard, or a tree

[caliper illustration]