IPA: //ʌnˈhɛlpfəl//
KK: /ʌnˈhɛlpfəl/
Not providing any support or assistance; not useful in a situation where help is needed.
The advice he gave was unhelpful and did not solve the problem.
Unhelpful → It is formed from "un-" (meaning not) and "helpful" (from Old English "helpful", meaning providing assistance). The word "unhelpful" means not providing assistance or support.
Think of 'not' ('un-') being added to 'helpful', which means providing assistance. This helps you remember that 'unhelpful' means not providing help.