by 1792, in the figurative sense of "person of bad character; member of some group guilty of offensive conduct that does little credit to the flock, family, or community to which he belongs," supposedly because a real black sheep (there was proverbially one in every flock) had wool that could not be dyed and thus was of less worth. But one black sheep in a flock was considered good luck by shepherds in Sussex, Somerset, Kent, Derbyshire. First known publication of Baa Baa Black Sheep nursery rhyme is in "Tommy Thumb's Pretty Song Book" (c. 1744).
"bubonic/pneumonic plague epidemic of 1347-51 in Europe," a modern name, introduced in English 1823 by Elizabeth Penrose's history of England. The contemporary 14c. name for it in most European languages was something like "the great dying" or simply "the plague;" in English it was the pestilence (or, looking back after its return in 1361-2, the first pestilence).
The term "Black Death" first turns up in 16c. Swedish and Danish chronicles, but it is used in reference to a visitation of plague in Iceland (which had been spared in the earlier outbreaks) in 1402-3 that carried off much of the population there. The exact sense of "black" is not clear. The term appears in English translations of the Scandinavian works from 1750s. It was picked up in German c. 1770 and applied to the earlier outbreak and was taken from there into English in that sense.
type of poisonous spider (Latrodectus mactans) in U.S. South, 1904, so called from its color and from the female's supposed habit of eating the male after mating (the males seem to get eaten more often before they mate, when they first enter the webs of the females, which have very poor eyesight). Sometimes also known as shoe-button spider. The name black widow is attested earlier (1830s) as a translation of a name of the "scorpion spider" of Central Asia.
also pigeonhole, 1570s as "a small recess for pigeons to nest in," from pigeon + hole (n.); later "hole in a dovecote for pigeons to pass in and out" (1680s). Extended meaning "a little compartment or division in a writing desk," etc. is from 1680s, based on resemblance. Hence, "an ideal compartment for classification of persons, etc." (by 1879). The verb is from 1840, "place or file away in a pigeon-hole." The figurative sense of "lay aside for future consideration" is by 1854, that of "label mentally" by 1870.
[Y]ou will have an inspector after you with note-book and ink-horn, and you will be booked and pigeon-holed for further use when wanted. ["Civilisation—The Census," Blackwood's Magazine, Oct. 1854]