A way to travel on a horse? (7)
I believe the answer is:
astride
'on a horse?' is the definition.
(I've seen this in another clue)
'a way to travel' is the wordplay.
'way to travel' becomes 'stride' (striding is a way of moving or travelling ).
'a'+'stride'='ASTRIDE'
(Other definitions for astride that I've seen before include "on horseback" , "With legs on each side" , "With a leg on both sides" , "On top of" , "With legs stretched apart - tirades (anag)" .)