The part of the chimney that is above the roof; it usually has several flues.(noun)
Gnu Collaboartive International Dictionary of English: licensed under The Code Project Open License (CPOL)
Use "chimneystack" in a sentence
"Far worse, following my too-brief possession of a spectacular position, was the chimneystack directly outside that completely screened any view."
"The old decommissioned chimneystack rose from the schoolyard like a tower erected in honour of learning."
"Seated on it, against no more romantic object than a blackened chimneystack over which some bumble creeper had been trained, they both pored over one book; both with attentive faces; Jenny with the sharper; Lizzie with the more perplexed."