adjective
Designed to keep water out and protect something from getting wet or damaged.
This jacket is waterproof.
Keep your phone in a waterproof case.
Good to know
Water-resistant gives limited protection from water. Waterproof gives much stronger protection.
Common phrases & grammar
waterproof jacket · waterproof boots · waterproof phone case · waterproof watch
something + be + waterproof
make + something + waterproof