Homonym: stopper (Closure)
A "stopper" is an object used to close or seal a container, preventing the contents from spilling or escaping. Commonly made from materials like rubber, cork, or plastic, stoppers are often found in bottles, jars, and other vessels. They help maintain the freshness of liquids, such as wine or soda, by keeping air out.
In addition to their use in containers, stoppers can also refer to devices that block or restrict flow in plumbing systems, such as sink or bathtub stoppers. These mechanisms allow users to fill or empty a basin by controlling the flow of water, making them essential in everyday household tasks.