watertight
/ˈwɔːtərtaɪt/Definitions
1. adjective
Having no openings and being resistant to water; not leaking.
“The engineer ensured that the boat’s hull was watertight before the voyage.”
2. noun
A compartment or tank in a ship or aircraft that is designed to be watertight.
“The watertight compartment was used to save the passengers from the sinking ship.”