leakproof (adj.)

• airtight
• bombproof
• bulletproof
• burglarproof
• fire-resisting
• fireproof
• flameproof
• foolproof
• hermetic
• proof
• rainproof
• resistant
• rustproof
• shatterproof
• shellproof
• soundproof
• stormproof
• tight
• waterproof
• watertight
• weatherproof