kind of swallow-like bird (Chelidon urbica), 1580s, from Scot. martoune (mid-15c.), from Middle French martin, from the masc. proper name in some sense. Writers in 17c. said it was named for St. Martin of Tours (d. 397 C.E.), whose festival day (Martinmas) is Nov. 11, about the time the birds depart.
