The term 'make less tense' can be summarized by the crossword solution 'DEFUSE, ' which is a six-letter word. Defusing is a process of reducing tension or hostility, usually in a situation where emotions are running high. It is often used to prevent an argument from escalating into a physical altercation. Defusing can also be used to reduce stress in a work environment or to help people relax in a tense situation.