Psychology or psychiatry.
a psych class
A psychologist; a psychiatrist.
To put (someone) into a required psychological frame of mind (also psych up).
To intimidate (someone) emotionally or using psychology (also psych out).
To treat (someone) using psychoanalysis.
Psychedelic.
curtains with psych colors
Psychiatric.
Indicating that one's preceding statement was false and that one has successfully fooled one's interlocutor. Also sike.
An interjection of surprised happiness.
Psych! I just found my missing bracelet!