What is laid over a thing to protect or conceal it. Also the outward face a work is met by.
Old French covrir (to cover, hide), from Latin cooperire (to cover completely), from com- (thoroughly) + operire (to close, shut); what is laid over a thing to protect or conceal it, extended to the outward face a work first meets the world with.
What is laid over a thing to protect or conceal it. By the same word, it is also the outward face a work is first met by, before anyone reaches what is underneath.