Sect by river shows way of life (7)
I believe the answer is:
culture
'way of life' is the definition.
(thesaurus)
'sect by river' is the wordplay.
'sect' becomes 'cult' (I've seen this before).
'by' says to put letters next to each other.
'river' becomes 'Ure' (river in Yorkshire).
'cult'+'ure'='CULTURE'
'shows' is the link.
(Other definitions for culture that I've seen before include "Refinement; grow (bacteria)" , "Growth in the laboratory" , "Set of ideas and values of a group" , "Customs of a group" , "Refinement - micro-organisms in a medium" .)