Pronunciation: (ôr"jē-as'tik),[key] —adj. 1. of, pertaining to, or having the nature of an orgy.
2. tending to arouse or excite unrestrained emotion: orgiastic rhythms. 3. Sociol. (of an expressive crowd) reaching a peak of emotional intensity, often of an ecstatic nature and frequently expressed by uninhibited behavior.