Got a whiff of fish (5)
I believe the answer is:
smelt
I believe this clue is a double definition.
'got a whiff of' is the first definition.
(I've seen this before)
'fish' is the second definition.
(smelt is a kind of fish)
(Other definitions for smelt that I've seen before include "was whiffy" , "23 [FISH]" , "Extract metal from twenty two" , "Extract metal from ore, fish" , "Small fish of salmon species" .)