The crossword solution for the term 'crumble under pressure' is 'WILT'. To WILT means to become limp or droop, usually due to lack of water or exposure to heat. It can also be used to describe a person who has become weak or exhausted due to stress or pressure. In this case, the term 'crumble under pressure' is referring to someone who has become overwhelmed and unable to cope with the demands placed upon them.