Casual get-together aboard cruise ship? (4)
I believe the answer is:
sesh
'casual get-together' is the definition.
I know nothing about this answer so I can't judge whether this works.
'aboard cruise ship?' is the wordplay.
'aboard' says the answer is hidden in the clue (the answer is aboard or within the clue).
'SESH' is hidden in the letters of 'cruise ship'.
Can you help me to learn more?
(Other definitions for sesh that I've seen before include "lots of drinks?" , "Sitting" .)