Needful \Need"ful\, a. 1. Full of need; in need or want; needy; distressing. [Archaic] --Chaucer. The needful time of trouble. --Bk. of Com. Prayer. 2. Necessary for supply or relief; requisite. All things needful for defense abound. --Dryden. -- {Need"ful*ly}, adv. -- {Need"ful*ness}, n.