The most common and most likely answer to this crossword clue is the 4 letter word AHAB
I've seen this crossword clue in The Guardian
A
H
A
B
More clues leading to the result AHAB
- A garment — absence of it exposes old king
- Expression of contempt about flipping sea captain
- Mahabarata contains OT king
- Norwegian group first to ban whaling captain
- Early on, a harpooner and boy?
- Starbuck’s boss‘s regular withdrawals of cash, maybe
- I’ve realised the sailor is a captain
- My sailor is one who hunted whales
- Penny has dropped, bowled and stumped skipper
- I’m surprised at British man appearing in Bible
Buddy explains!

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.