Leaves in a paper bag, perhaps (3)

I believe the answer is:
tea
'leaves' is the definition.
(as in tea leaves)
'a paper bag perhaps' is the wordplay.
I cannot quite understand how this works, but
'a' is within the answer.
The remaining letters 'te' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'in' is the link.
Can you help me to learn more?
(Other definitions for tea that I've seen before include "Plant" , "Plantation product" , "Afternoon meal; drink" , "tips for the cup?" , "Earl Grey?" .)
