Lunatic can also be described as crazy, manic, wild, delirious, and psycho/psychopath.
<span>maniac, madman, madwoman, imbecile, psychopath, psychotic; fool, idiot;eccentric; informalloony, nut, nutcase, nutjob, head case, psycho, moron, screwball, crackpot, fruitcake, fruit loop, <span>loon</span></span>