### Clue: Primarily, spiritualist ultimately finding ihs?n? (4)
### Answer: SUFI 
 ### Explanation: Primarily, spiritualist ultimately finding ihs?n? (4)
First letters ('primarily') of '**S**piritualist **U**ltimately **F**inding **I**hsan', Sufism is Islamic mysticism, much concerned with finding ihsan, perfection of worship.