Like a ruler turned to drink (5)
I believe the answer is:
lager
'drink' is the definition.
(lager is a kind of drink)
'like a ruler turned' is the wordplay.
I cannot quite see how this works, but
'a' is present in the answer.
'ruler' could be 'er' (abbreviation for Elizabeth Regina) and 'er' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'to' acts as a link.
Can you help me to learn more?
(Other definitions for lager that I've seen before include "Continental beer" , "drink in the bar?" , "Regal kind of beer" , "The drink could be regal" , "Bottom-fermented beer" .)