1802, name of a "magic lantern" exhibition brought to London in 1802 by Parisian showman Paul de Philipstal, the name an alteration of French phantasmagorie, said to have been coined 1801 by French dramatist Louis-Sébastien Mercier as though to mean "crowd of phantoms," from Greek phantasma "image, phantom, apparition" (see phantasm) + second element probably a French form of Greek agora "assembly" (but this may have been chosen more for the dramatic sound than any literal sense). Transferred meaning "shifting scene of many elements" is attested from 1822. Related: Phantasmagorical.
phantasmagoria phan·tas·ma·go·ri·a (fān-tāz'mə-gôr'ē-ə) or phan·tas·ma·go·ry (fān-tāz'mə-gôr'ē)
n. phan·tas·ma·go·ri·as or phan·tas·ma·go·ries
A fantastic sequence of haphazardly associative imagery, as seen in dreams or fever.