Dormition

Dormition is the Latin-English word preferred by many English-speaking Orthodox over Assumption, to describe the end of the Theotokos' earthly life. It means "falling asleep," ie, death.

In Roman Catholic doctrine, the Assumption of Mary refers to her body being raised to heaven by God at the end of her life. The Latin Church no longer remembers that Mary first died before being assumed into heaven, and says it doesn't know whether she died or not, and that it's not important. However, many Orthodox see in the related Latin doctrine of her Immaculate Conception without Original Sin, an implication that she is immortal, since death came with sin (Romans 5:12) and if she is without the Sin of the World, she never died. (We still call her immaculate, but not in the Catholic sense.)

So Orthodox use of the words Dormition or Falling Asleep in theology, parish names, or the name of the Great Feast of August 15, is often to underline that the Theotokos died, and within a couple days of her death, her tomb was found empty, her body having been glorified and reunited with her soul in heaven -- as will happen to all the Saints at the end.

This is another example of how we and others use the same words but mean different things.

(PS: Some Orthodox and parishes, however, do use the word Assumption. But all of us Orthodox remain united in doctrine!)