The most common and most likely answer to this crossword clue is the 7 letter word ABALONE
I've seen this crossword clue in The Times
A
B
A
L
O
N
E
More clues leading to the result ABALONE
- Edible shellfish in middle of seabed singly
- A Yankee sausage, not Yankee shellfish
- A black sole circles a shellfish
- Seafood, dab and sole — though last of cod is gone
- Leading academic’s endless nonsense
- A poison coating Lake Ontario’s premier shellfish
- Boatman unequalled
- Without anyone else to carry a couple of barrels of shellfish for instance
- He works on board by himself with shell
- Single sailor gets seafood
Buddy explains!
The straight part
We know that "shellfish" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case shellfish = abalone.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ABALONE mean?
ABALONE noun- An edible univalve mollusc of the genus Haliotis, having a shell lined with mother-of-pearl.
- The meat of the aforementioned mollusc.