Small excess of wine to satisfy thirst (5)
I believe the answer is:
slake
'satisfy thirst' is the definition.
(I've seen this before)
'small excess of wine' is the wordplay.
I cannot quite see how this works, but
'small' could be 's' (abbreviation - e.g. clothes size) and 's' is found within the answer.
The remaining letters 'lake' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for slake that I've seen before include "Quench (one's thirst)" , "Assuage" , "Satisfy one's thirst" .)