Withdraw membership as Dee's upset about the church (6)
I believe the answer is:
secede
'withdraw membership' is the definition.
'secede' can be an answer for 'withdraw' (I've seen this before). I'm not sure about the 'membership' bit.
'dee's upset about the church' is the wordplay.
'upset' is an anagram indicator.
'about' indicates putting letters inside.
'the church' becomes 'CE' (Church of England).
'dees' anagrammed gives 'sede'.
'sede' placed around 'ce' is 'SECEDE'.
'as' acts as a link.
Can you help me to learn more?
(Other definitions for secede that I've seen before include "'Withdraw, break away (6)'" , "Withdraw formally from membership or alliance" , "Break away (politically)" , "Make a formal withdrawal" , "'Withdraw formally, from a political body perhaps (6)'" .)