Chimney stacks serve an important purpose in homes, but they can be difficult to describe when seeking synonyms. One option is to use the term "flue," which refers to the passage in a chimney that allows smoke and gases to escape. Another possible synonym is "stack," which is a more general term for a tall, narrow structure. "Vent," "exhaust," and "pipe" are all additional synonyms for chimney stacks, as they all relate to the action of releasing gas or air from a confined space. When seeking alternative phrases, one could use the description "smokestacks," or even use the more traditional name "chimneys" instead.