American lab returned single snail (7)
I believe the answer is:
abalone
'snail' is the definition.
The definition and answer can be both animals as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'american lab returned single' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'returned' says the letters should be written in reverse.
'single' becomes 'one' (similar in meaning).
'lab' back-to-front is 'bal'.
'a'+'bal'+'one'='ABALONE'
Can you help me to learn more?
(Other definitions for abalone that I've seen before include "Seafood" , "Sea food must be found" , "shellfish for instance" , "One lives in a shell" , "sea mollusc" .)