Helpful, a.
Furnishing help; giving aid; assistant; useful; salutary. Heavens make our presence and our practices Pleasant and helpful to him! Shak. -- Help"ful*ly, adv. -- Help"ful*ness, n. Milton.
Shades of meaning
Fernald lists helpful only as an antonym, under pernicious, pitiful.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given