Fish from nasty drains eaten for starter? (7)
I believe the answer is:
sardine
'fish' is the definition.
(sardine is a type of fish)
'nasty drains eaten for starter?' is the wordplay.
'nasty' indicates anagramming the letters (a nasty or wrong spelling).
'for starter?' suggests taking the first letters (I've seen 'for starters' mean this).
The first letter of 'eaten' is 'e'.
'drains' with letters rearranged gives 'sardin'.
'sardin'+'e'='SARDINE'
'from' acts as a link.
(Other definitions for sardine that I've seen before include "Fish (often tinned)" , "Young pilchard" , "A diner's small fish" , "Swimmer" , "(Cramped?) fish" .)