Walk in street on journey (6)
I believe the answer is:
stride
'walk' is the definition.
(stride can mean to walk around)
'street on journey' is the wordplay.
'street' becomes 'st' (abbreviation).
'on' means one lot of letters go next to another (in a down clue, letters appear on others).
'journey' becomes 'ride' (riding is a kind of journeying).
'st'+'ride'='STRIDE'
'in' acts as a link.
(Other definitions for stride that I've seen before include "Long decisive step" , "use your legs!" , "A big step forward" , "Extended footstep" , "Long pace" .)