'pacesetter' definitions:

Definition of 'pacesetter'

(from WordNet)
noun
A leading instance in its field; "the new policy will be a pacesetter in community relations" [syn: pacesetter, pacemaker]
noun
A horse used to set the pace in racing [syn: pacer, pacemaker, pacesetter]

Definition of 'pacesetter'

From: GCIDE
  • pacesetter \pacesetter\ n. A horse used to set the pace in racing.
  • Syn: pacer, pacemaker. [WordNet 1.5]

Synonyms of 'pacesetter'

From: Moby Thesaurus