Joke aboard ship about head of entertainment (3-5)
I believe the answer is:
one-liner
'joke' is the definition.
(I know that one-liner is a type of joke)
'aboard ship about head of entertainment' is the wordplay.
'aboard' indicates putting letters inside.
'ship about' becomes 'onliner' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'head of' suggests taking the first letters.
The first letter of 'entertainment' is 'e'.
'onliner' placed around 'e' is 'ONE-LINER'.
Can you help me to learn more?
(Other definitions for one-liner that I've seen before include "Single sentence jokes" , "Witty remark in single short sentence" , "Witty remark consisting of a short sentence" , "Flat, smooth" , "Short joke - witty remark" .)