Sailor introduced to African as believer in free will (11)
I believe the answer is:
libertarian
'believer in free will' is the definition.
(libertarians believe in individual liberty)
'sailor introduced to african' is the wordplay.
'sailor' becomes 'tar' (slang term for a sailor).
'introduced to' is an insertion indicator.
'african' becomes 'liberian' (Liberia is in Africa).
'tar' put into 'liberian' is 'LIBERTARIAN'.
'as' is the link.
(Other definitions for libertarian that I've seen before include "Believer in free will" , "Free-thinking" , "Champion of freedom" , "individualist?" , "One backing freedom" .)