Beverage that stimulates partner (4)
I believe the answer is:
mate
This clue might be a double definition.
'beverage that stimulates' is the first definition.
'mate' can be an answer for 'beverage' (mate is a kind of beverage). I'm not sure about the remainder of the definition.
'partner' is the second definition.
(I know that partner can be written as mate)
Can you help me to learn more?
(Other definitions for mate that I've seen before include "provides solution to chess problem" , "Spouse or informal friend" , "assistant" , "Team (anag.)" , "Sailor" .)