From the Catholic Education Resource Center:
However, the belief surrounding the dormition is intrinsically linked with the assumption of our Blessed Mother, body and soul, into Heaven.
The Byzantine Emperor Mauritius (582-602) established the Feast of the Dormition of the Blessed Virgin Mary on Aug. 15 for the Eastern Church, which celebrated our Lady's death and assumption. (Some historians speculate that the celebration was already widespread before the Council of Ephesus in 431.) By the end of the sixth century, the West likewise celebrated the feast under the title of "the Assumption."
I shall await your apology, though I expect none to come.
Dormition means death/falling asleep. The quote you provided says nothing different. The fact that to Catholics the death of the Virgin is linked to the entirely separate belief in the Assumption is neither here nor there. I will further note for the record that the Orthodox Church does not regard the Assumption as church doctrine. It is a pious belief held by many, but it is not regarded as a dogma as it is by the Romans.
Apology?
For what; exactly??