not influenced by, showing, or involving personal feelings.
Sophie finds facebook very unpersonal.
by Markman78 December 10, 2008
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
A person who you had a close and meaningful relationship with and who was a big part of your life, but no longer is, usually due to a Falling Out or breakup. This person is typically an ex girlfriend, ex boyfriend, good friend, or family member that defined your past life, but seems to have vanished from your current life completely, whether you like it or not. In many cases, one will pretend that this person no longer exists, or never existed in the first place, due to negative past memories of said person.

This is synonymous with a "somebody that I used to know", from the 2012 Gotye song, and comes from the newspeak word "unperson" in the George Orwell novel 1984, meaning a person who has been seemingly erased from existence.
"Sophie dumped me out of the blue with no good reason, moved away, and never talked to me again. She's an unperson to me now, and caused me a huge amount of pain."
by Ganymedian May 14, 2020