What does the cryptic crossword clue "Casual get-together aboard cruise ship? (4)" mean?

The definition is "Casual get-together". The wordplay uses a hidden word. Hidden in "casual get-together aboard cruiSE SHip?" The answer is SESH.

Casual get-together aboard cruise ship? (4)

Independent Cryptic #11818 | 1 Down | 2024-08-26 flower