[cal.i.per] n [alter. of caliber] (1588) 1 a: any of various measuring instruments having two usu. adjustable arms, legs, or jaws used esp. to measure diameter or thickness--usu. used in pl. "a pair of ~s" b: a device consisting of two plates lined with a frictional material that press against the sides of a rotating wheel or disc in certain brake systems
2: thickness esp. of paper, paperboard, or a tree
[2]caliper vt -pered ; -per.ing (1876): to measure by or as if by calipers