ENHYPOSTASIA
Etymology
Noun
enhypostasia (plural not attested)
(Christianity (Christology)) The state of the human nature of Jesus Christ being entirely dependent on, and not existing independently of, the divine nature of God as a whole (which is the hypostasis of the Holy Trinity comprising God the Father, God the Son, and God the Holy Spirit), or individual persons of the Trinity such as the Father and the Holy Spirit.
Usage notes
Merriam-Webster Online indicates the existence of the plural form enhypostasias, but it is currently unattested. However, enhypostases, the plural of enhypostasis, is attestable.
Source: Wiktionary