annunciation
Concise Oxford English Dictionary © 2008 Oxford University Press:
annunciation/ənʌnsiˈeɪʃn/
▶noun
- 1 (the Annunciation) the announcement of the Incarnation by the angel Gabriel to Mary (Luke 1:26–38).
■ a Church festival that commemorates this, held on 25 March (Lady Day).
- 2 formal or archaic the announcement of something.
'annunciation' also found in these Oxford entries:

