-proof

a combining form meaning “resistant, impervious to” that specified by the initial element: burglarproof; childproof; waterproof.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for -proof

-proof

adjective, combining form

secure against (damage by); (make) impervious towaterproof; mothproof; childproof

Word Origin for -proof

from proof (adj)

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012