Source of tea in tea cups? (5)
I believe the answer is:
china
'source of tea' is the definition.
'china' can be an answer for 'tea' (I've seen this before). I am not sure about the 'source of' bit.
'in tea cups?' is the wordplay.
'tea' becomes 'cha' (cha is a type of tea).
'cups?' means one lot of letters goes inside another (inserted letters are held or cupped).
'in' put within 'cha' is 'CHINA'.
Can you help me to learn more?
(Other definitions for china that I've seen before include "Beijing's country" , "Household ceramics" , "bud" , "Ceramics; country" , "Asian country" .)