Suited a busy type going across a river (6)
I believe the answer is:
became
'suited' is the definition.
('become' can be a synonym of 'suit')
'a busy type going across a river' is the wordplay.
'a busy type going' becomes 'bee' (I am not sure about this - if you are sure you should believe this answer much more).
'across' indicates putting letters inside.
'a river' becomes 'cam' (river in Cambridge, England).
'bee' placed around 'cam' is 'BECAME'.
Can you help me to learn more?
(Other definitions for became that I've seen before include "Turned into" , "Developed into something" , "Grew" , "Looked good" , "Got to be" .)