Allan Kardec's term for the spirit body, astral body, fluidic body.

(perí in greek, or surrounding) name given to the semi-material body of the spirit. It has material properties that can be perceived by mediums. In incarnate spirits, it is the link or intermediary body between the spirit and the material body. In disembodied spirits, it constitutes the fluidic body.

AllanKardec's term for the spirit body, astral body, fluidicbody.