It is then an integral portion of the Faith fixed by Ecumenical Council, a portion of it which you hold as well as I, that the Blessed Virgin is Theotocos, Deipara, or Mother of God; and this word, when thus used, carries with it no admixture of rhetoric, no taint of extravagant affection,—it has nothing else but a well-weighed, grave, dogmatic sense […]
Source: wiktionary