recondite (adj.)

• abstract
• abstruse
• academic
• arcane
• blind
• buried
• cabalistic
• close
• clouded
• concealed
• covered
• covert
• cryptic
• dark
• deep
• difficult
• enigmatic
• erudite
• esoteric
• hard
• heavy
• hermetic
• hidden
• impenetrable
• incommunicado
• incomprehensible
• inexplicable
• latent
• learned
• mysterious
• mystic
• mystical
• obscure
• occult
• opaque
• pedantic
• profound
• runic
• scholarly
• secluded
• secret
• sequestered
• sibylline
• transcendental
• undecipherable
• underground
• unfathomable
• unknown