Remain second best (4)
I believe the answer is:
stop
'remain' is the definition.
The answer and definition can be both related to change as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
'second best' is the wordplay.
'second' becomes 's' (common abbreviation).
'best' becomes 'top' (top can mean the very best).
's'+'top'='STOP'
Can you help me to learn more?
(Other definitions for stop that I've seen before include "Prevent - desist" , "Come to a halt" , "Pack it in - bar" , "Withhold large amount raised" , "This watch is used to time races" .)