look up any word, like full-donald:
 
1.
To be fired or "laid off" in an unceremonious fashion without warning and to have the company not acknowledge it is to become an "unperson"
Engineer 1: What happened to Jim and Carl? They were helping us make this deadline.

Engineer 2: Jim? Carl? Who are those cats?

Engineer 1: They both gave status at yesterday's 8:30 standing meeting, you shared an office with Jim..

Engineer 2 in a low voice: They became unpersons, they were fired. Nobody knows why.
by A. Hacker June 28, 2006
 
2.
An un-person is someone who is unattractive, unclean, undesireable, unworthy, unfunny, unsmart, ect.

Anything you wouldnt want to be called that starts with the prefix "un".
Cara is a typical un-person.
by SweetKarma April 25, 2008