v. & n.
--v.
1. tr. help, benefit.
2 refl. (foll. by of) profit by; take advantage of.
3 intr. a provide help. b be of use, value, or profit.
--n. (usu. in neg. or interrog. phrases) use, profit (of no avail; without avail; of what avail?).
Etymology: ME f. obs. vail (v.) f. OF valoir be worth f. L valere