(slang) To say something and not mean it or mean the opposite. (see
sike) Messing with someone's mind. Derived from the psychological term "
psyche" which is defined as 1) The mind; 2)
The spirit or soul; 3) the mind as the center of thought, emotion, and behavior. (wikipedia)
(
on the beach) "Dude, look at that smooth hot guy over there with
the swimmer's build!"
('victim' turns to find a really unattractive man)
"
PSYCH!"