Watery medicine? (5)
I believe the answer is:
tonic
This could be a double definition.
'watery' is the first definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I can't see?
'medicine?' is the second definition.
(I know that tonic is a type of medicament)
Can you help me to learn more?
(Other definitions for tonic that I've seen before include "something providing a boost" , "Restorative that invigorates" , "Stimulant" , "Invigorating drink" , "Keynote of a scale" .)