Undue influence is a legal term used to describe a situation in which one person uses their power or authority to PRESSURE another person into making a decision that they would not have made otherwise. It is often used in the context of wills and trusts, where an individual may be coerced into changing their will or trust in favor of another person. The crossword solution for the term 'undue influence' is 'PRESSURE, ' which accurately describes the type of influence that is being exerted on the other person.