WEATHERPROOF
weatherproof
(adjective) able to withstand exposure to weather without damage; “weatherproof electric wiring”; “a weatherproof coat”
weatherproof
(verb) make resistant to bad weather
Source: WordNet® 3.1
Etymology
Adjective
weatherproof (comparative more weatherproof, superlative most weatherproof)
Capable of resisting damage caused by the weather.
Verb
weatherproof (third-person singular simple present weatherproofs, present participle weatherproofing, simple past and past participle weatherproofed)
To make something resistant to damage caused by the weather.
Source: Wiktionary
Weath"er*proof`, a.
Definition: Proof against rough weather.
Source: Webster’s Unabridged Dictionary 1913 Edition