Affable countryman crossing lake (8)
I believe the answer is:
pleasant
'affable' is the definition.
(pleasant can mean affable or friendly)
'countryman crossing lake' is the wordplay.
'countryman' becomes 'peasant'.
'crossing' means one lot of letters goes inside another.
'lake' becomes 'L' (geographical abbreviation).
'peasant' placed around 'l' is 'PLEASANT'.
(Other definitions for pleasant that I've seen before include "Refreshing" , "Charming" , "Delightful" , "Attractive" , "Satisfying, likeable" .)