An opponent. Usually someone who you or your friends have a large amount of hate towards. Usually used when one wants to be secret about his or her hate towards other. Also a foul butthole smell.

Adjective or Noun.
Adam: Son of a bitch our teacher is such a douche face.

Jack: No he's a Grundee. Get it right.

Adam: Grundee. Nice.
by SAMTASTIC24 May 29, 2011
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