'chimneystack' definitions:

Definition of 'chimneystack'

(from WordNet)
noun
The part of the chimney that is above the roof; usually has several flues

Definition of 'chimneystack'

From: GCIDE
  • chimneystack \chimneystack\ n. the part of the chimney that is above the roof; it usually has several flues. [WordNet 1.5] chimneysweep