ahorse
1. [ adverb ] on horseback
Synonyms: ahorseback
Examples:

"managed to escape ahorse" "policeman patrolled the streets ahorseback"

2. [ adverb ] on the back of a horse
Synonyms: horseback ahorseback
Examples:

"he rode horseback to town" "managed to escape ahorse" "policeman patrolled the streets ahorseback"

3. [ adjective ] traveling on horseback
Synonyms: ahorseback
Examples:

"a file of men ahorseback passed by"

Related terms: moving