dampproof

[ damp-proof ]
/ ˈdæmpˌpruf /

adjective

resistant to dampness or the effects of dampness.

verb (used with object)

to make dampproof.

Origin of dampproof

First recorded in 1880–85; damp + -proof
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019