Fast food being unavailable (6)
I believe the answer is:
starve
'fast' is the definition.
(to fast is to refrain from eating food)
'food being unavailable' is the wordplay.
I cannot really see how this works, but
'food' could be 'e' (E is an example) and 'e' is found in the answer.
'being' could be 'star' (star is a kind of being) and 'star' is found within the answer.
A single letter 'v' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for starve that I've seen before include "Die from lack of food" , "Die of hunger" , "Stop feeding" , "Suffer great hunger" , "Suffer from food deprivation" .)