Restaurant’s pronounced gamble over hotel on river (10)
I believe the answer is:
steakhouse
'restaurant's' is the definition.
(steakhouse is a kind of restaurant)
'pronounced gamble over hotel on river' is the wordplay.
'pronounced' shows a homophone (sound like).
'gamble' becomes 'stake' (stake is a kind of gamble).
'over' is a charade indicator (letters next to each other).
'hotel on river' becomes 'house' (I can't justify this - if you can you should believe this answer much more).
'stake' sounds like 'steak'.
'steak'+'house'='STEAKHOUSE'
(Other definitions for steakhouse that I've seen before include "Scene of grilling" , "Specialist restaurant" , "Eating-place" , "Meat restaurant" .)