[adj] not allowing air or gas to pass in or out [adj] having no weak points; "an airtight defense"; "an airtight argument"
gas-tight, invulnerable, tight
ballproof, bombproof, bulletproof, burglarproof, close, compact, corrosionproof, dampproof, dustproof, dusttight, fast, fireproof, fire-resisting, firm, flameproof, foolproof, gasproof, gastight, hermetic, hermetically sealed, holeproof, impervious to, le