Also, waif.Nautical. a signal given by waving a flag.
Origin: 1535–45; back formation from late Middle English waughter armed escort vessel < Dutch or Low German wachter watchman; in some senses confused with waff
1513, "to carry over water," back-formation from obs. wafter "convoy ship" (1482), from M.Du. or M.L.G. wachter "a guard," from wachten "to guard," related to waken "rouse from sleep" (see wake (1)). The meaning "pass through air or space, float" is first attested 1704, and