shirk (v.)

1630s, "to practice fraud or trickery," also a noun (1630s, now obsolete) "a needy, disreputable parasite" [OED], perhaps from German schurke "scoundrel, rogue, knave, villain" (see shark (n.)). Sense of "evade one's work or duty" first recorded 1785, originally in slang. Related: Shirked; shirking.