Pronunciation: (hi-ster'i-kul), [key]
1. of, pertaining to, or characterized by hysteria.
2. uncontrollably emotional.
3. irrational from fear, emotion, or an emotional shock.
4. causing hysteria.
5. suffering from or subject to hysteria.
6. causing unrestrained laughter; very funny: Oh, that joke is hysterical!
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.