Male composer in female clothing on ship (6)
I believe the answer is:
brahms
'male composer' is the definition.
(Johannes Brahms, 1833-1897)
'in female clothing on ship' is the wordplay.
'in' is an insertion indicator.
'female' becomes 'bess' (woman's name).
'clothing' says to hollow out the word (remove centre letters).
'on ship' becomes 'rahm' (I am not sure about this - if you are sure you should believe this answer much more).
'bess' with its centre taken out is 'bs'.
'bs' enclosing 'rahm' is 'BRAHMS'.
Can you help me to learn more?
(Other definitions for brahms that I've seen before include "Composer of a well-known lullaby published in 1868" , "Musician" , "He scored" , "German barman" , "Composer of A German Requiem" .)