1. designed or constructed to prevent liquid or gas from escaping or entering

Examples

• The new water bottle has a leakproof cap.
• Make sure the container is leakproof before storing chemicals.
• The leakproof design prevents spills in your backpack.
• We need leakproof boots for the rainy season.
• The thermos features a leakproof seal.
• This leakproof lunch box keeps food fresh.