1. draughtproof - Adjective
2. draughtproof - Verb
draughtproof (comparative more draughtproof, superlative most draughtproof) (British spelling)
That prevents the entry of draughts.
draughtproof (third-person singular simple present draughtproofs, present participle draughtproofing, simple past and past participle draughtproofed)
To seal an opening, so as to prevent the entry of draughts.