Hysterics/hɪˈsterɪks/ Definition 1 of 3Pro Tip 1/3Emotional Trigger Used when something triggers extreme laughter or crying. He couldn't tell the story without going into hysterics. Pro Tip 2/3Overwhelming Response It implies that the person’s response is beyond their control. The surprise party threw her into hysterics. Pro Tip 3/3Group Effect Often occurs in a group setting where emotion is shared. The entire class was in hysterics during the play.