Definition of "Homoousion"

Homoousion

/hɒməʊˈuːzɪɒn/

noun
uncountable
1. (theology) The inclusion of the term ὁμοούσιος (homooúsios, “of one essence”) in the Nicene Creed to describe the principle that the Son is ‘of one substance’ with the Father (as opposed to the Homoiousion).
  Quotations
  The campaign to get rid of the Homoousion from Christian credal statements split the Church in the empire for another half-century and more.
  2009, Diarmaid MacCulloch, A History of Christianity, Penguin, published 2010, page 215