Definition of homoiousian in English:

homoiousian

noun

historical
  • A person who held that God the Father and God the Son are of like but not identical substance.

    Compare with homoousian
    • ‘The arguments between the homoiousian and homoousians would be hysterically ridiculous if it weren't for the amount of blood shed over the letter ‘i’.’
    • ‘The Arian controversy was a Christological dispute that began in Alexandria between the followers of Arius, the Arians; the followers of St. Alexander of Alexandria, known as homoousians; and a third group, known as homoiousians.’
    • ‘Constantius at first supported these homoiousians but soon transferred his support to the homoousians, led by Acacius, who affirmed that the Son was ‘like’ the Father.’
    • ‘In 381, the Council of Constantinople reaffirmed the credo of Nicaea and condemned the semi-Arians, the homoiousians.’
    • ‘In the Council of Nicaea, for instance, the bishops had to choose between homoousian and homoiousian to describe Jesus' nature: Is He of ‘one’ substance with the Father, or is He of ‘like’ substance to the Father?’

Origin

Late 17th century (as an adjective in the sense ‘of similar but not identical substance’): via ecclesiastical Latin from Greek homoiousios, from homoios like + ousia essence, substance. The noun dates from the mid 18th century.

Pronunciation:

homoiousian

/ˌhɒmɔɪˈuːsɪən/