The Collaborative International Dictionary of English v.0.48:

Inferiae \In*fe"ri*[ae]\, n. pl. [L., fr. inferus underneath.]
   (Rom. Antiq.)
   Sacrifices offered to the souls of deceased heroes or
   friends.
   [1913 Webster]

The Devil's Dictionary (1881-1906):

INFERIAE,n.  [Latin]  Among the Greeks and Romans, sacrifices for
propitiation of the _Dii Manes_, or souls of the dead heroes; for the
pious ancients could not invent enough gods to satisfy their spiritual
needs, and had to have a number of makeshift deities, or, as a sailor
might say, jury-gods, which they made out of the most unpromising
materials.  It was while sacrificing a bullock to the spirit of
Agamemnon that Laiaides, a priest of Aulis, was favored with an
audience of that illustrious warrior's shade, who prophetically
recounted to him the birth of Christ and the triumph of Christianity,
giving him also a rapid but tolerably complete review of events down
to the reign of Saint Louis.  The narrative ended abruptly at the
point, owing to the inconsiderate crowing of a cock, which compelled
the ghosted King of Men to scamper back to Hades.  There is a fine
mediaeval flavor to this story, and as it has not been traced back
further than Pere Brateille, a pious but obscure writer at the court
of Saint Louis, we shall probably not err on the side of presumption
in considering it apocryphal, though Monsignor Capel's judgment of the
matter might be different; and to that I bow -- wow.