Esoteric

adjective

1a. designed for or understood by the specially initiated alone < a body of ~ legal doctrine

b. of or relating to a small group

2a. limited to a small circle <~pursuits>

b. Private, Confidental

ORIGIN mid 17th cent.: from Greek es?terikos, from es?ter?, comparative of es? ‘within,’ from es, eis ‘into.’ Compare with exoteric .