A typically generic person in a famous or notable organization, such as a sports team or political party who is destined to not stand out.

The sketchy notability requirements usually will qualify them for a low trafficked Wikipedia page.
John Smith is a Z grade congressmen from the 7th Wyoming Congressional District

Fatguy Runblock is a Z grade lineman of the Buffalo Bills.

Pintapout McJobber is a Z grade WWE dark match jobber.
by Blargstar December 1, 2010
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a so called celeribity from shows like Big Brother, only popular for the time the show is on, but when its over they are never heard off again
Robbo - "Hey wotever happened to Stacey from Big Bro??"

Johno - "Dude that was last season, she is a Z - Grade Celebrity
by Peter Alexander July 13, 2008
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