1) A mental state where one can not tell the difference between reality and their imagination.
3) A type of behaviour where a person may act in a way that may be seen as "uncool" or "weird" (and doesn't care).
3) The only way to fly.
The state of suffering a severe psychiatric disease which causes extremely abnormal behaviour or loss of touch with reality (psychosis), most commonly associated with schizophrenia and bipolar illness (the manic phase).