noun ( BrE ) (also cali·per NAmE , BrE ) / ˈkælɪpə(r); NAmE /
1.
callipers [ pl. ] an instrument with two long thin parts joined at one end, used for measuring the diameter of tubes and round objects (= the distance across them) :
a pair of callipers
2.
( BrE ) ( NAmE brace ) [ C , usually pl. ] a metal support for weak or injured legs