plural noun

things understood by or meant for a select few; recondite matters or items.

Origin of esoterica

1925–30; < New Latin, noun use of neuter plural of Greek esōterikós esoteric Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Word Origin and History for esoterica

by 1807, Modern Latin, from plural of Greek esoterikos "pertaining to those within" (see esoteric).

Online Etymology Dictionary, © 2010 Douglas Harper