draftproof draftproof /ˈdræftpruf/

adjective

1. [ N. American] Sealed to the outside to prevent currents of cool air  ( draftproof [ N. American] , draughtproof [British] )
   sealed to the outside to prevent currents of cool air
   

verb

1. [ N. American] Seal to keep stop cool air flowing in  ( draftproof [ N. American] , draughtproof [British] )
   seal to keep stop cool air flowing in