Small restaurant in club is tropical (6)
I believe the answer is:
bistro
'small restaurant' is the definition.
(I've seen this before)
'in club is tropical' is the wordplay.
'in' says the answer is hidden in the clue.
'BISTRO' is hidden within 'club is tropical'.
(Other definitions for bistro that I've seen before include "Cafe/restaurant" , "Small informal French restaurant" , "Coming out of restaurant" , "Cheap restaurant" , "'Small, inexpensive restaurant (6)'" .)