Enjoy longer life not working on river (7)
I believe the answer is:
outwear
'enjoy longer life' is the definition.
(outwear can mean to last longer than)
'not working on river' is the wordplay.
'not working' becomes 'out' (out can mean on strike).
'on' says to put letters next to each other.
'river' becomes 'wear' (I've seen this before**).
'out'+'wear'='OUTWEAR'
(Other definitions for outwear that I've seen before include "Exhaust" , "Last longer than others" , "Top dressing" , "ride" , "Drain" .)