cestui que trust \-(ˌ)kē.ˈtrəst, -ˌkwe.ˈ-\noun (pluralcestuis que trustorcestuis que trustent \-ˈtrəst\) Etymology: Anglo-French, literally, he for whom (the) trust (is held) : a person who has the equitable and beneficial interest in property the legal interest in which is vested in a trustee