Genial head of government in West African state (6)
I believe the answer is:
benign
'genial' is the definition.
(similar in meaning)
'head of government in west african state' is the wordplay.
'head of' says to take the initial letters.
'in' is an insertion indicator.
'west african state' becomes 'Benin' (country in West Africa).
The initial letter of 'government' is 'g'.
'g' put into 'benin' is 'BENIGN'.
(Other definitions for benign that I've seen before include "Genial; not harmful" , "Meaning no harm" , "Kindly or non-malignant" , "sweet" , "Medically curable" .)