Definition of: hypostasis

(hī·pos′tə·sis, hi-) noun
1. That which forms, either in fact or hypothesis, a groundwork or support for anything; a basis.
2. Philos. A distinct individual subsistence; also, a logical substance.
3. Theol. Any one of the persons of the Trinity; also, the separate personal subsistence of each of the three persons of the Trinity in one divine substance.
4. Med. A settling down of a fluid of the body.
5. Pathol. A morbid deposition of sedimentary matter within the body. [<L <Gk. hypostasis substance, subsistence <hypo- under + histhastai stand, middle voice of histanai cause to stand]