What is the meaning of Flue?

A pipe or duct that carries gaseous combustion products away from the point of combustion (such as a furnace).

An enclosed passageway in which to direct air or other gaseous current along.

A woolly or downy substance; down, nap; a piece of this.

In an organ flue pipe, the opening between the lower lip and the languet.

Alternative form of flew (shallow, flat)

fly

fluently

second-person singular present active imperative of fluō

Alternative form of flowen

a fly

Alternative form of flu

Source: wiktionary.org