late 14c., "acquire, get," from Old French encrochier "seize, fasten on, hang on (to), cling (to); hang up, suspend," literally "to catch with a hook," from en- "in" (see en-(1)) + croc "hook," from Old Norse krokr "hook" (see crook, n.). Sense extended to "seize wrongfully" (c.1400), then "trespass" (1530s). Related: Encroached; encroaches; encroaching.