from
The Collaborative International Dictionary of English v.0.48
Oratory \Or"a*to*ry\, n.; pl. {Oratories}. [OE. oratorie, fr. L.
oratorium, fr. oratorius of praying, of an orator: cf. F.
oratoire. See {Orator}, {Oral}, and cf. {Oratorio}.]
A place of orisons, or prayer; especially, a chapel or small
room set apart for private devotions.
[1913 Webster]
An oratory [temple] . . . in worship of Dian.
--Chaucer.
[1913 Webster]
Do not omit thy prayers for want of a good oratory, or
place to pray in. --Jer. Taylor.
[1913 Webster]
{Fathers of the Oratory} (R. C. Ch.), a society of priests
founded by St. Philip Neri, living in community, and not
bound by a special vow. The members are called also
{oratorians}.
[1913 Webster]