Stop on the way (4)
I believe the answer is:
rest
'stop' is the definition.
(to take a rest is to stop)
'on the way' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'the way' becomes 'st' (abbreviation for street).
're'+'st'='REST'
(Other definitions for rest that I've seen before include "Surplus" , "Change is as good as this, they say" , "'Relax, pause from work (4)'" , "Leisure" , "Pole in Crucible?" .)