Luny is a term used to describe someone who is behaving in a crazy or insane manner. There are several synonyms for luny, including mad, deranged, unhinged, insane, crazed, loony, nutty, bonkers, and wacky. These words all describe someone who is not behaving in a rational or normal way and can be used interchangeably with luny. Other synonyms for luny include batty, demented, maniacal, and psychotic. These words all convey the same sense of someone who is not mentally stable and is behaving in an abnormal way. While the use of such terms may not be politically correct, they are still commonly used to describe someone who is acting irrationally.