A willing subject is someone who is eager and willing to comply with a request or command. The term 'willing subject' can be used in many different contexts, such as in legal documents, in the workplace, or in relationships. In this case, the crossword solution for the term 'willing subject' is 'ESTATE, ' which refers to a person's property or possessions. An ESTATE is typically owned by an individual and can include land, buildings, money, and other assets. A willing subject is someone who is willing to give up their ESTATE in order to comply with a request or command.