outriderPronunciation: /ˈaʊtrʌɪdə/Translate outrider | into Italian Definition of outrider noun a person in a motor vehicle or on horseback who goes in front of or beside a vehicle as an escort or guard. US a mounted official who escorts racehorses to the starting post. US a mounted herdsman who prevents cattle from straying beyond a certain limit. Derivatives outriding noun outrider in other Oxford dictionaries Definition of outrider in the US English dictionary