Was maybe apt to be sniffed at (5)
I believe the answer is:
smelt
'sniffed at' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for smelt that I've seen before include "half a guinea" , "Small silvery fish" , "Stank" , "were high" , "23 [FISH]" .)