Answer:
undue influence
Explanation:
Undue influence consists in the gaining of an unfair advantage by an impulsive use of power by a stronger party against a weaker one in the form of some unfair and improper conduct, some coercion from outside, some overreaching, some form of cheating, and generally, though not always, some personal advantage obtained by the stronger party. It is directed at conduct within a relationship which justifies the conclusion that the disposition or agreement was not the result of a free exercise of the disponer's will.