: an enclosed passageway for directing a current: such as
: a channel in a chimney for conveying flame and smoke to the outer air
: a pipe for conveying flame and hot gases around or through water in a steam boiler
: an air channel leading to the lip of a wind instrument

Example Sentences

Recent Examples on the Web Maher is a comedian and talk-show host who last year famously advised against getting the swine flue shot. Keith Kloor, Discover Magazine, 25 Nov. 2010 But, chimneys and flue liners are designed to contain and direct smoke. Bradley Ford, Popular Mechanics, 15 Dec. 2022 Chimney and fireplace damage can be hard to see without being on the roof or inside the flue itself, particularly with masonry designs. Tribune News Service, al, 14 Sep. 2022 Without them, rain can go down the flue and deteriorate the mortar joints. Tribune News Service, al, 14 Sep. 2022 Make sure the chimney flue is open and that the vent has been swept at least once during the last year. Joe Mario Pedersen, orlandosentinel.com, 28 Jan. 2022 All of the dead collapsed and died after being overcome by smoke while trying to descend down the stairway, which acted as a flue for the heavy smoke. Fox News, 17 Jan. 2022 Just inside the front door to the left sits one of only three split-flue fireplaces in Old Louisville. Lennie Omalza, The Courier-Journal, 24 Nov. 2021 If using a fireplace, make sure the chimney flue is open and stay awake while the fire is burning. Dr. Mishal Reja, ABC News, 19 Feb. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'flue.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


origin unknown

First Known Use

1582, in the meaning defined above

Time Traveler
The first known use of flue was in 1582

Dictionary Entries Near flue

Cite this Entry

“Flue.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flue. Accessed 28 Jan. 2023.

Kids Definition


: an enclosed passageway for directing a current
especially : a channel in a chimney for carrying flame and smoke to the outer air
Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

The Great British Vocabulary Quiz

  • union jack speech bubble
  • Named after Sir Robert Peel, what are British police called?
Name That Thing

You know what it looks like… but what is it called?

Solve today's spelling word game by finding as many words as you can with using just 7 letters. Longer words score more points.

Can you make 12 words with 7 letters?