adj. 1 a of use; serviceable. b producing or able to produce good results (gave me some useful hints). 2 colloq. highly creditable or efficient (a useful performance). make oneself useful perform useful services. useful load the load carried by an aircraft etc. in addition to its own weight. usefully adv. usefulness n.
USEFUL
Meaning of USEFUL in English
Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012