1 definition by CommonMistake

When you think you know someone, but then you realise you've just seen them on Facebook... sometimes via a friend or sometimes via Facebook Stalking.
Guy 1 "I'm sure I know that girl..."

Guy 2 "I think she's just Facebook Familiar"

...

Guy 1 "I said 'Hey' to this girl the other day, I was sure I knew her from somewhere... but she disagreed"

Guy 2 "Facebook Familiarity - It's a bitch"
by CommonMistake March 10, 2011
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