Pollution from pass encountered around North (10)
I believe the answer is:
defilement
'pollution' is the definition.
('defilement' can be a synonym of 'pollution')
'pass encountered around north' is the wordplay.
'pass' becomes 'defile' (defile is a kind of pass**).
'encountered' becomes 'met' ('meet' can be a synonym of 'encounter').
'around' is an insertion indicator.
'north' becomes 'n' ('N' can be a synonym of 'north').
'met' enclosing 'n' is 'ment'.
'defile'+'ment'='DEFILEMENT'
'from' is the link.
(Other definitions for defilement that I've seen before include "Desecration" , "Pollution" .)