American going west spots bears (8)
I believe the answer is:
sustains
'bears' is the definition.
(both can mean endures)
'american going west spots' is the wordplay.
'american' becomes 'US' (United States).
'going west' says the letters should be written in reverse (letters heading to the west or left).
'spots' becomes 'stains' (spot can mean a stain or mark).
'us' reversed gives 'su'.
'su'+'stains'='SUSTAINS'
(Other definitions for sustains that I've seen before include "Bears" , "It's Susan (anag.)" , "Supports physically or mentally" , "keeps going" , "Supports, keeps alive" .)