Meaning of USEFUL in English
/ ˈjuːsfl; NAmE / adjective
useful (to do sth) | useful (to sb) | useful (for sth / for doing sth) that can help you to do or achieve what you want :
a useful gadget
It can be useful to write a short summary of your argument first.
He might be useful to us.
These plants are particularly useful for brightening up shady areas.
Don't just sit watching television— make yourself useful !
This information could prove useful .
Your knowledge of German may come in useful (= be useful in a particular situation) .
Some products can be recycled at the end of their useful life.
( BrE , informal ) good; of the right standard
SYN competent :
He's a very useful player.
► use·ful·ly / -fəli; NAmE / adverb :
The money could be more usefully spent on new equipment.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005