The term 'be in stitches' is an idiom that means to be laughing uncontrollably. The two crossword solutions for this term are 'LAUGH' (5 letters) and 'dielaughing' (11 letters). 'LAUGH' is a verb that describes the action of making a sound with one's voice that expresses amusement or joy. 'Dielaughing' is an adverb that describes the intensity of the laughter, suggesting that it is so loud and intense that it could last until one dies.