Real Dictionary

slate
Slate is a dark-grey rock that can be easily split into thin layers. Slate is often used for covering roofs.

slate in American English 1
a hard, fine-grained, metamorphic rock, typically formed from shale, that cleaves naturally into thin, smooth-surfaced layers
to cover with slate
noun: a fine-grained rock formed by the metamorphosis of clay, shale, etc., that tends to split along parallel cleavage planes, usually at an angle to the planes of stratification

slate in American English 2
to punish severely, as by thrashing
transitive verb: to sic or set a dog on (a person or animal)

slate in British English 1
noun: a compact fine-grained metamorphic rock formed by the effects of heat and pressure on shale. It can be split into thin layers along natural cleavage planes and is used as a roofing and paving material

slate in British English 2
to criticize harshly; censure