What does the word flue mean?

Usage examples for flue

  1. The winding wooden staircase was black as a flue. – A Crooked Mile by Oliver Onions
  2. " I must speak to Mr Wentworth, if he comes, to keep on Thompson," she said to herself, and then gave a momentary sigh at the thought of the new flue, which was as good as her own invention, and which it had cost her both time and money to arrange to her satisfaction. – The Perpetual Curate by Mrs [Margaret] Oliphant