Definition of flue :
1. A compartment or division of a chimney for conveying flame and smoke to the outer air.
2. A passage way for conducting a current of fresh, foul, or heated air from one place to another.
3. A pipe or passage for conveying flame and hot gases through surrounding water in a boiler; - distinguished from a tube which holds water and is surrounded by fire. Small flues are called fire tubes or simply tubes.
4. An inclosed passage way for establishing and directing a current of air, gases, etc.; an air passage
5. In an organ flue pipe, the opening between the lower lip and the languet.
6. Light down, such as rises from cotton, fur, etc.; very fine lint or hair.
air pipe (part of speech: noun)
- There was no flue for a stove in our part of the house. - "The-Life-of-Me-an-autobiography", Johnson, Clarence Edgar.
- I shall slip down the flue With this letter for you, So softly, for fear I your slumbers might break. - "In The Yule-Log Glow, Vol. IV (of IV)", Harrison S. Morris.
- In the winter, I am persuaded, I could not exist in rooms thus closed up, with stoves heated in their manner, for they only put wood into them twice a day; and, when the stove is thoroughly heated, they shut the flue, not admitting any air to renew its elasticity, even when the rooms are crowded with company. - "Letters written during a short residence in Sweden, Norway, and Denmark", Mary Wollstonecraft.