overzealous
1. [ adjective ] marked by excessive enthusiasm for and intense devotion to a cause or idea
Synonyms: fanatical rabid fanatic
Examples:

"rabid isolationist"

Related terms: passionate
Similar spelling:   overjealous
  overcredulous
  overserious
  overgenerous
  overcloud
  overexploit
  oversize
  overcall
  oversized