(a.) Alt. of Hermetical.

abstruse airtight arcane ballproof bombproof bulletproof burglarproof cabalistic censored classified cloistered close closed compact concealed corrosionproof cryptic dampproof dark deep dustproof dusttight enigmatic esoteric fast fire-resisting fireproof firm flameproof foolproof gasproof gastight heavy hermetical hermetically sealed hidden holeproof hush-hush impervious impervious to latent leakproof lightproof lighttight mysterious noiseproof occult oilproof oiltight profound proof proof against punctureproof rainproof raintight recluse resistant restricted rustproof sealed secluse seclusive secret sequestered shatterproof shellproof shut fast smokeproof smoketight smothered snug soundproof staunch stifled stormproof stormtight suppressed tight top secret ulterior unbreatheable under security under wraps undisclosable undisclosed undivulgable undivulged unrevealable unrevealed unspoken untellable untold unutterable unuttered unwhisperable water-repellant waterproof watertight weatherproof windproof windtight