Cowls are protective coverings for chimneys or vents that are used to prevent debris and rain from entering. There are several synonyms which can be used for cowls, depending on their intended purpose. For example, "flue cover," "vent hood," and "chimney cap" can all be used to refer to a cowl. Similarly, "exhaust hood," "smokestack cover," and "duct cap" may be used to describe a cowl that is designed to protect industrial exhaust outlets. Whether it is for residential or industrial use, these synonyms for cowls provide a clearer and more specific description of their purpose.