Definition of outrunner in US English:

outrunner

noun

  • 1A person who or animal which runs along the outside or outer side of something, as an attendant who runs ahead of or beside a carriage, a dog leading a team of sledge dogs, etc. Also figurative: one who goes about gathering or spreading intelligence; a forerunner, an advance party (now chiefly historical).

  • 2A projection or outshoot of a forest, mountain range, or some other physical feature.

noun

rare
  • A person who or thing which outruns something.

Origin

Late 16th century; earliest use found in John Florio (1553–1625), author and teacher of languages. From out- + runner<br>mid 19th century. From outrun + -er. Compare earlier outrunner.

Pronunciation

outrunner

/ˈaʊtˌrʌnə/