Ship’s officer potty about old queen (9)
I believe the answer is:
commodore
'ship's officer' is the definition.
'commodore' can be an answer for 'officer' (commodore is a kind of officer). I am not sure about the 'ship's' bit.
'potty about old queen' is the wordplay.
'potty' becomes 'commode' (synonyms).
'about' is an insertion indicator.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'queen' becomes 'r' (abbreviation for regina, e.g. in ER ).
'o'+'r'='or'
'commode' enclosing 'or' is 'COMMODORE'.
Can you help me to learn more?
(Other definitions for commodore that I've seen before include "senior officer" , "Naval officer" , "President of a yacht club" , "Naval rank junior to rear-admiral" , "officer, surely?" .)