Free, free at last to travel (4)
I believe the answer is:
ride
'travel' is the definition.
(riding is a kind of travelling)
'free free at last' is the wordplay.
'free' becomes 'rid' ('rid' can be a synonym of 'free'**).
'at last' suggests the final letters.
The last letter of 'free' is 'e'.
'rid'+'e'='RIDE'
'to' is the link.
(Other definitions for ride that I've seen before include "Be transported" , "Travel by horse, bus, etc" , "Travel (on a bike, perhaps)" , "spin > lift > pedal" , "Sally" .)