First to span river in Dodge (4)
I believe the answer is:
scam
'dodge' is the definition.
(thesaurus)
'first to span river' is the wordplay.
'first to' says to take the initial letters.
'river' becomes 'cam' (river in Cambridge, England).
The first letter of 'span' is 's'.
's'+'cam'='SCAM'
'in' is the link.
(Other definitions for scam that I've seen before include "Rip-off" , "Con trick" , "fiddle" , "Screw" , "Fraudulent trick or swindle" .)