Seafood for a bachelor, companionless (7)
I believe the answer is:
abalone
'seafood' is the definition.
(type of sea snail)
'a bachelor companionless' is the wordplay.
'bachelor' becomes 'BA' (the qualification: Bachelor of Arts).
'companionless' becomes 'lone' (I've seen this in another clue).
'a'+'ba'+'lone'='ABALONE'
'for' acts as a link.
(Other definitions for abalone that I've seen before include "Seafood" , "shellfish for instance" , "Sea food must be found" , "One lives in a shell" , "Ear-shaped shell" .)