"one who shirks duty or danger," 1799, agent noun from shirk (v.).
Entries linking to shirker
shirk v.
1630s, "to practice fraud or trickery, live by one's wits," also a noun (1630s) "a needy, disreputable parasite" [OED], of uncertain origin. Perhaps from German schurke "scoundrel, rogue, knave, villain" (see shark (n.)).
Both older senses are obsolete. The meaning "go evasively or slyly, slink, sneak away" is from 1580s; hence that of "evade one's work or duty," recorded by 1785, originally slang or colloquial. It also was used by 1787 in the sense of "evade (someone), avoid meeting, dodge." Related: Shirked; shirking.