[AIVC, Air infiltration and ventilation glossary, 1992]:an airstream with a significant downward directional component of velocity. Often occurs adjacent to cold surfaces. It may be generated artificially by air curtains, air doors etc.

[EN 12792-2003, 113]:removable plug or key operated draw-off cock intended to permit the removal of incoming liquids or condensates.

[AIVC, Air infiltration and ventilation glossary, 1992]:the action of filling the gaps around doors and windows, in order to prevent outside cold air leaking into the building, causing draughts.(see weatherstripping; caulking).