hypostatic

Richard Norris, in The Christological Controversy:

Since ... the characteristic properties of both natures and substances are kept intact and come together in one person, lowliness is taken on by majesty, weakness by power, mortality by eternity, and the nature which cannot be harmed is united to the nature which suffers, in order that the debt which our condition involves may be discharged. In this way, as our salvation requires, one and the same mediator between God and human beings, the human being who is Jesus Christ, can at one and the same time die in virtue of the one nature and, in virtue of the other, be incapable of death. That is why true God was born in the integral and complete nature of a true human being, entire in what belongs to him and entire in what belongs to us.