Meaning

noun shackle that consists of a metal loop that can be locked around the wrist; usually used in pairs

verb confine or restrain with or as if with manacles or handcuffs

origin1775, from hand + cuff (“end of shirtsleeve”). Possibly influenced by Old English handcops, from hand + cops (“fetter, chains”), but due to lack of continuity (centuries between Old English and modern term), generally analyzed as a re-invention.

Etymology from Wiktionary, CC BY-SA 3.0