Uniformed employee in firm, initially managing task on river (14)
I believe the answer is:
commissionaire
'uniformed employee in firm initially' is the definition.
I can't tell whether this defines the answer.
'managing task on river' is the wordplay.
'managing' becomes 'commission' (commission is a kind of managing).
'task on river' becomes 'aire' (I can't explain this - if you can you should believe this answer much more).
'commission'+'aire'='COMMISSIONAIRE'
Can you help me to learn more?
(Other definitions for commissionaire that I've seen before include "Uniformed doorman" , "Uniformed door attendant" .)