The term 'BURST INTO LAUGHTER' can be summarized by two crossword solutions: 'CRACKUP' and 'BROKEUP'. 'CRACKUP' is a 7-letter word that means to suddenly start laughing uncontrollably, usually in response to something funny. 'BROKEUP' is also a 7-letter word that means to separate or divide into pieces, often used to describe the end of a relationship. Both words can be used to describe the act of bursting into laughter, as it can be a reaction to something humorous or a sign of relief after a difficult situation.