Webster's Dictionary 
(1): ( n.) The collective gods of a people, or a work treating of them; as, a divinity of the Greek pantheon.
(2): ( n.) A temple dedicated to all the gods; especially, the building so called at Rome.
The Nuttall Encyclopedia 
A temple in Rome, first erected by Agrippa, son-in-law of Augustus, circular in form, 150 ft. in height, with niches all round for statues of the gods, to whom in general it was dedicated; it is now a church, and affords sepulture to illustrious men. Also a building in Paris, originally intended to be a church in honour of the patron saint of Paris, but at the time of the Revolution converted into a receptacle for the ashes of the illustrious dead, Mirabeau being its first occupant, and bearing this inscription, Aux grands hommes la patrie reconnaissant ; it was subsequently appropriated to other uses, but under the third republic it became again a resting-place for the ashes of eminent men.
Cyclopedia of Biblical, Theological and Ecclesiastical Literature 
Bibliography Information McClintock, John. Strong, James. Entry for 'Pantheon'. Cyclopedia of Biblical, Theological and Ecclesiastical Literature. https://www.studylight.org/encyclopedias/eng/tce/p/pantheon.html. Harper & Brothers. New York. 1870.