Guide To Go Green - presumably you'd get that in a bar in Grenoble (10)
I believe the answer is:
chartreuse
'green presumably you'd get that in a bar in grenoble' is the definition.
'chartreuse' can be an answer for 'green' (chartreuse is a kind of green). I'm unsure of the rest of the definition.
'guide to go' is the wordplay.
I cannot really understand how this works, but
'to go' could be 're' (I've seen this in other clues) and 're' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for chartreuse that I've seen before include "Green or yellow liqueur made by monks" , "green liquid" , "Green-yellow liqueur" , "Pale green-yellow colour" , "drink" .)
