noun

1. an informer
2. a strikebreaker; esp., a professional strikebreaker
3. a person regarded as contemptible, obnoxious, etc.

Etymology: Ger, lit., finch, used since the 17th c. as generalized pejorative; adopted (c. 1740) by students at Jena for nonmembers of fraternities (prob. in allusion to the wild bird in contrast to the caged canary); later extended to those not in organizations, esp. unions

intransitive verb