A corker is a type of closure used primarily for sealing bottles, especially wine and champagne. Made from the bark of the cork oak tree, corkers are valued for their ability to create an airtight seal, which helps preserve the quality and flavor of the liquid inside. They are also lightweight and biodegradable, making them an environmentally friendly option. In addition to their use in bottling, the term "corker" can also refer to something remarkable or surprising. For example, a "corker of a joke" might be one that is particularly funny or unexpected. This usage highlights the versatility of the word in everyday language.