Keep in good condition or state (8)
I believe the answer is:
maintain
I believe this is a double definition.
'keep in good condition' is the first definition.
(I've seen this in another clue)
'state' is the second definition.
(I've seen this before)
'or' acts as a link.
(Other definitions for maintain that I've seen before include "Keep going" , "Claim" , "Keep up - carry on" , "Assert" , "Keep (a building) in good condition" .)