(formerly) a writing tablet made of slate
"The children used their slates to practice spelling before they could afford paper and pencils."
a fine-grained metamorphic rock that can be split into thin layers
"The geologist carefully sliced through the slate to examine its fine-grained structure and ability to split into thin, smooth sheets."
A fine-grained homogeneous sedimentary rock composed of clay or volcanic ash which has been metamorphosed so that it cleaves easily into thin layers.
"The geologist collected a sample of slate from the quarry to study its ability to cleave into thin, smooth sheets for roofing tiles."
In plain English: A slate is a flat piece of stone that people used to write on with chalk before erasing it for reuse.
"The teacher asked us to write our names on the black slate at the front of the room."
Usage: Use "slate" as a noun to refer specifically to the fine-grained, layered sedimentary rock used for roofing or writing tablets. As an adjective, describe surfaces with its characteristic cool gray color rather than using it metaphorically without context.
To cover with slate.
"The old cottage was slated to protect it from the harsh winter rain."
Having the bluish-grey/gray colour of slate.
"The sky turned a deep slate color just before the storm arrived."
In plain English: Slate describes something that is clean and ready to start fresh without any past mistakes holding it back.
"The teacher decided to slate any student who cheated on the test."
A surname.
"Her uncle, Mr. Slate, was known throughout the village for his generous donations to the local school."
The word slate comes from Middle English sclate, which was borrowed from Old French esclate meaning "broken piece" or "shard." Its ultimate origin traces back to a Germanic root related to splitting or breaking apart.