An extractor is a machine that pulls air out of a room — hot air, greasy air, or air that smells bad. In a kitchen it usually sits above the cooker and sucks steam and cooking smell away so the room does not fill with smoke. In a factory it may sit over a bench and pull fumes away from the people working there. The job is simple: it extracts air, the way you pull juice out of a fruit, and sends that air outside. Though actually, in everyday British English people often say the whole name extractor fan; Americans more often say exhaust fan, or range hood for the kitchen kind. It is a practical, slightly technical word. You meet it on appliance boxes, in building plans, and when someone is complaining that the kitchen still smells.