Travel free, heading east (4)
I believe the answer is:
ride
'travel' is the definition.
(riding is a kind of travelling)
'free heading east' is the wordplay.
'free' becomes 'rid' ('rid' can be a synonym of 'free'**).
'heading east' becomes 'e' (abbreviation).
'rid'+'e'='RIDE'
(Other definitions for ride that I've seen before include "Travel in or be carried on" , "Sit on (a horse/vehicle)" , "Take a trip" , "Be transported" , "Lie at anchor" .)