A lid or cover is part of a container, and serves as the closure or seal, usually one that completely closes the object. Lids can be placed on small containers such as tubs as well as larger lids for open-head pails and drums. Some lids have a security strip or a tamper-evident band to hold the lid on securely until opening is desired or authorized. These are usually irreversible to indicate that the container has been opened. They can be made of varying materials ranging from plastic to metal.
Lids have been found on pottery dating back as far as 3100 BC. Ancient Egyptian canopic jars with lids held the organs of mummified bodies as early as 2686 BC. The coffee lid market is valued at roughly $180 million. An estimated 14 billion lids were sold in 2009 in the United States. Some containers such as tubs or jars now have a plastic film heat sealed onto the container: this is often called a lidding film.
The word is used metaphorically, as in "keeping the lid on the secret" and "flipped his lid". Other meanings or usages include: