King taken in by Alcoholics Anonymous group (4)
I believe the answer is:
abba
'group' is the definition.
(pop group)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for abba that I've seen before include "Group winning the 1974 Eurovision Song Contest in Brighton" , "Palindromic 70s pop group" , "Waterloo singers" , "Swedish pop music group" , "Father (NT)" .)