Slate
Usually a shortened or altered form of a surname linked to Sleat in Scotland, though it may also overlap with occupational forms related to slate or slater.
The #5,796 most common surname in the United States (2010 Census) — about 1 in every 51,725 Americans shares it.
Etymology
The strongest historical clue is that Slate was treated by some 19th-century surname writers as a variant of Sleat, the place-name in Inverness-shire. That would make it a locational surname, originally meaning someone from that district. A second, looser connection is with Middle English words for slate and with the occupational surname Slater, but the sources here do not make Slate itself a straightforward job-name.
History
Lower specifically called Slate an Edinburgh surname and suggested a link with Sleat in Inverness-shire. In the historical record, Slate appears more as a spelling variant or local form than as a large, independent surname. Modern bearers in the United States are relatively few, which fits a name that has remained uncommon and regionally rooted.
Origin
Regions
Variant spellings
Fun fact
One 19th-century source explicitly described Slate as an Edinburgh surname, showing how surnames could drift far from their original place-name roots.
From the historical record
“slippery, etc.] SLATE, a var. of Slett, q.v. SLATER SLATTE «}'• Sclatep.”
— Surnames of the United Kingdom: a concise etymological dictionary (2 vols in 1)