'ahorse' definitions:

Definition of 'ahorse'

(from WordNet)
adverb
On the back of a horse; "he rode horseback to town"; "managed to escape ahorse"; "policeman patrolled the streets ahorseback" [syn: horseback, ahorse, ahorseback]
adjective
Traveling on horseback; "a file of men ahorseback passed by" [syn: ahorse(p), ahorseback(p)]