Alternatively have one drink but where did it come from? (6)
I believe the answer is:
origin
'where did it come from?' is the definition.
The answer is a location as well as being a singular noun. This is suggested by the definition.
'alternatively have one drink' is the wordplay.
'alternatively' becomes 'or'.
'have' means one lot of letters go next to another.
'one' becomes 'i' (Roman numeral).
'drink' becomes 'gin' (gin is a kind of drink).
'or'+'i'+'gin'='ORIGIN'
'but' is the link.
Can you help me to learn more?
(Other definitions for origin that I've seen before include "Place where something begins" , "Where axes cut" , "base" , "For a start" , "Starting point or cause" .)