Facebook-hot is a term used when describing someone who only appears to be attractive on their facebook pictures, but in real life is non attractive.
Steve: I went on a date with Cara last night.
Ron: Cara? Her pro pic is so hot. You're lucky.
Steve: No, actually it turns out that she's only facebook-hot.
A girl or boy who you have never met, looks attractive on facebook or on any other social network, but in real life when you finally meet them, you think wow that person is not attractive at all and has disgusting characteristic. Facebook pretty shows that pictures can be deceiving.
Ah, dude this girl pictures on facebook was hot but when i saw her in person, she had all this acne on her.
I'd totally do her facebook body, but not her real body.
"How come you called that date off with that boy?"
"He's nice, and he had a facebook hot picture, but in real life he's not.
The theory that people always look hotter on facebook.
Usually caused through the use of photoshop to better ones self image and the picking of certain pictures that randomly happen to look better through lighting effects/angles.
Dude 1:WOAH did you see Anna's pictures on facebook?!?!
Dude 2:That chick is rape ugly in real life... man don't you know about the hotter on facebook theory???.... stay away
Dude 1:Ewww check out that chick over at that lunch table, it looks like a dog attacked her
Dude 2: WTF, I was checking her out on facebook last night and she was SMOKIN.