a movable top or cover (hinged or separate) for closing the opening at the top of a box, chest, jar, pan, etc.
"he raised the piano lid"
The top or cover of a container.
"She replaced the lid on the jar to keep the leftovers fresh."
In plain English: A lid is a cover that goes on top of something to keep it closed or protected.
"She put the lid back on the jar to keep the cookies fresh."
To put a lid on (something).
"The manager decided to put a lid on the employees' complaints after hours of discussion."
In plain English: To lid something means to cover it with a tight-fitting top so nothing can get inside or out.
"She decided to lid the pot tightly so the soup would not spill over while simmering on high heat."
The word "lid" comes from Old English hlid, which originally meant a covering or shield. It traveled into modern usage to describe the top part of an open container that covers it.