n.
Pronunciation: ˌ o ̇ r- ə - ' to ̇ r- ē - ˌ ō , ˌ är-
Function: noun
Inflected Form: plural -ri · os
Etymology: Italian, from the Oratorio di San Filippo Neri (Oratory of Saint Philip Neri) in Rome
Date: 1731
: a lengthy choral work usually of a religious nature consisting chiefly of recitatives, arias, and choruses without action or scenery