Song from Zaire associated with many a fanatic (6)
I believe the answer is:
zealot
'a fanatic' is the definition.
(thesaurus)
'song from zaire associated with many' is the wordplay.
'song from zaire' becomes 'zea' (I can't explain this - if you can you should give a lot more credence to this answer).
'associated with' says to put letters next to each other.
'many' becomes 'lot' (I've seen this before).
'zea'+'lot'='ZEALOT'
Can you help me to learn more?
(Other definitions for zealot that I've seen before include "Fervent, perhaps militant, proponent" , "A fanatic, driven person" , "One ardent for cause" , "Fervent, even militant, proponent of something" , "Fanatic, usually religious" .)