Melissa goes off without goals (7)
I believe the answer is:
aimless
'without goals' is the definition.
('goal' can be 'aim' (aim is a kind of goal) so maybe 'without goals' can be ''aimless')
'melissa goes off' is the wordplay.
'goes off' indicates an anagram.
'melissa' anagrammed gives 'AIMLESS'.
(Other definitions for aimless that I've seen before include "Like characters in 5D {WAITING FOR GODOT]" , "Drifting - Melissa (anag)" , "lacking direction" , "without sense of purpose" , "Without purpose or plan" .)