Meaning of “hysterical” - Learner’s Dictionary

hysterical

adjective uk us /hɪˈsterɪkəl/
NO CONTROL

If someone is hysterical, they cannot control their feelings or behaviour because they are extremely frightened, angry, excited, etc.:

hysterical laughter
As soon as Wendy saw the blood, she became hysterical.
FUNNY informal
hysterically adverb

They all thought it was hysterically funny.

(Definition of “hysterical” from the Cambridge Learner’s Dictionary © Cambridge University Press)