Old prince pouring some more (7)
I believe the answer is:
rainier
This clue is a double definition.
'old prince' is the first definition.
(Rainier III of Monaco)
'pouring some more' is the second definition.
(Other definitions for rainier that I've seen before include "This is more likely to pour down" , "Prince of Monaco, married to Grace Kelly, d. 2005" , "more drops?" , "More wet - Monaco's late prince" , "Mountain" .)