Needless, a.
1. Having no need. [Obs.] Weeping into the needless stream. Shak.
2. Not wanted; unnecessary; not requiste; as, needless labor; needless expenses.
3. Without sufficient cause; groundless; cuseless. "Needless jealousy." Shak. -- Need"less*ly, adv. -- Need"less*ness, n.
Shades of meaning
Fernald lists needless only as an antonym, under necessary.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given