1. Sealed to the outside to prevent currents of cool air
   "They installed draughtproof windows to keep the house warm in winter";
   - draftproof [N. Amer]

1. Seal to keep stop cool air flowing in
   "We need to draughtproof the doors before the cold weather sets in";
   - draftproof [N. Amer]

Derived forms: draughtproofed, draughtproofing, draughtproofs