late O.E., from S.W. Midlands dial. eovese (sing.), from O.E. efes "edge of a roof," from P.Gmc. *ubaswa-/*ubiswa (cf. O.H.G. obasa "porch, hall, roof," Goth. ubizwa "porch," Ger. oben "above"), from the root of over
. Treated as plural and new singular form eave emerged c.1580.