hys ‧ ter ‧ i ‧ cal /hɪˈsterɪk ə l/ BrE AmE adjective
1 . unable to control your behaviour or emotions because you are very upset, afraid, excited etc:
Janet became hysterical and began screaming.
Everyone in the studio burst into hysterical laughter.
2 . informal extremely funny SYN hilarious :
It was absolutely hysterical! I’ve never laughed so much.
—hysterically /-kli/ adverb