impermeable
adjectiveUK /ɪmˈpɜːmiəbl/
US /ɪmˈpɜːrmiəbl/
Something impermeable does not let water or air pass through it.
The raincoat is impermeable, so the rain stays outside and you stay dry.
RELATED WORDS
OTHER MEANINGS
2. Not allowing a liquid or gas to spread through a material.
The impermeable clay layer keeps groundwater from seeping down.
3. Impossible to pass through or enter.
The dense hedge formed an impermeable wall around the garden.
4. Not affected or influenced by something.
He seemed impermeable to criticism and kept working calmly.