concealed (adj.)

• abstruse
• arcane
• blind
• buried
• cabalistic
• camouflaged
• censored
• classified
• close
• closed
• clouded
• covered
• covert
• cryptic
• dark
• disguised
• enigmatic
• esoteric
• guarded
• hermetic
• hidden
• hush-hush
• imperceptible
• incommunicado
• indiscernible
• insensible
• invisible
• latent
• mysterious
• obscure
• occult
• privy
• recondite
• restricted
• secluded
• secret
• sequestered
• sightless
• smothered
• stifled
• submerged
• suppressed
• ulterior
• unapparent
• underground
• undisclosed
• unknown
• unnoticed
• unobserved
• unperceivable
• unperceived
• unrealized
• unrevealed
• unseeable
• unseen
• unspoken
• untellable
• untold
• unutterable
• unuttered
• viewless