stopper
n.a small object, like a cork or a plug, that you put into the top of a bottle or jar to close it. It keeps the liquid inside and prevents air from getting in.
n.an object, such as a plug or bung, designed to seal the opening of a container. Often made of glass, cork, or rubber to ensure an airtight or watertight fit.
“She put the glass stopper back in the perfume bottle.”
“After pouring the wine, he replaced the decorative stopper to keep the remaining liquid fresh.”
“The chemist carefully inserted the ground-glass stopper into the flask to prevent the volatile reagents from evaporating during the overnight reaction.”
Commonly refers to the removable closure of a bottle, distinct from a screw-on cap.
“Espanyol stopper Marko Dmitrovic made a good save to stop Mbappe after he got in behind on the right of the area.”
From stop + -er.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.