c.1300, "neck armor, gorget," from Old French coler "neck, collar" (12c., Modern French collier), from Latin collare "necklace, band or chain for the neck," from collum "the neck," from PIE *kwol-o- "neck" (cognates: Old Norse and Middle Dutch hals "neck"), literally "that on which the head turns," from root *kwel- (1) "move round, turn about" (see cycle, n.). Late 14c. as "border at the neck of a garment."

1550s, "to grab (someone) by the collar or neck," from collar, n.. Meaning "to capture" is attested from 1610s. Related: Collared; collaring. As a past participle adjective, collared "wearing a collar" is from late 14c.