The term 'laughs hysterically' can be represented by two crossword solutions: SHRIEKS (7 letters) and FALLSABOUT (10 letters). SHRIEKS is an onomatopoeic word that describes a loud, high-pitched sound made when someone is laughing uncontrollably. FALLSABOUT is a phrase that implies someone is laughing so hard that they are unable to remain standing or in control of their body. Both words describe a situation where someone is laughing uncontrollably, often with a great deal of energy and enthusiasm.