Old Indian rule for recycling glass? (3)
I believe the answer is:
raj
'old indian rule' is the definition.
(I've seen this in another clue)
'recycling glass?' is the wordplay.
'recycling' shows that the letters should be reversed in order (the letters cycle back).
'glass?' becomes 'jar' (I have seen 'Glass of beer ' mean 'jar' so perhaps 'glass' could also mean 'jar').
'jar' backwards is 'RAJ'.
'for' is the link.
(Other definitions for raj that I've seen before include "Jar (anag.)" , "Indian government" , "Sovereignty" , "British rule (in 19dn)" , "Indian rule in India" .)