Job in street by river (4)
I believe the answer is:
post
'job' is the definition.
(post is a kind of job)
'street by river' is the wordplay.
'street' becomes 'st' (abbreviation).
'by' is a charade indicator (letters next to each other).
'river' becomes 'Po' (Italian river).
'st' put after 'po' is 'POST'.
'in' is the link.
(Other definitions for post that I've seen before include "trading establishment" , "Member < to comment on website" , "Upright - letters" , "Stake, job or mail" , "Publish' mail' job" .)