coverslip
/ˈkʌvərˌslɪp/Definitions
1. noun
A thin glass plate used to cover a microscopic specimen and protect it from dust and other contamination.
“The biologist placed a coverslip over the prepared sample to prevent it from getting damaged.”
2. noun
A thin glass plate used as a protective covering for a microscopic specimen.
“The student carefully placed a coverslip over the slide to avoid contamination.”