Definitions for outriderˈaʊtˌraɪ dər
Random House Webster's College Dictionary
a mounted attendant riding before or beside a carriage.
a mounted rider who accompanies a racehorse to the post.
Category: Common Vocabulary
a person who goes in advance.
Origin of outrider:
an escort who rides ahead (as a member of the vanguard)
A guide or escort, especially one who rides in advance