curvature of the spine, 1704, Modern Latin, from Greek lordosis, from lordos "bent backwards," a word of uncertain origin, with possible cognates in Armenian, Celtic, and Germanic. From 1941 in reference to the mating position assumed by some female mammals. Related: Lordotic.
c. 1500, transitive, "to equal, rival," 1590s as "to match as mates, couple, join in marriage," from mate (n.1). Also, of animals, "to pair for the purpose of breeding" (c. 1600). Intransitive sense of "be joined in companionship" is from 1580s. Related: Mated; mating.
also lovebird, 1590s, small species of West African parrot, noted for the remarkable attention mating pairs pay to one another; figurative sense of "a lover" is attested from 1911.
Hold hands, you lovebirds. [Emil Sitka]
"the mating with only one female or wife," by 1859, from Greek monos "single, alone" (see mono-) + gynē "female, woman" (from PIE root *gwen- "woman"). Related: Monogynist; monogynous. Used a few years earlier in translations of Fourier, where it refers to the quality of those who "excel in some one function."
"periodically recurring sexual excitement in animals; animal mating season" (originally of deer), early 15c., from Old French rut, ruit, from Late Latin rugitum (nominative rugitus) "a bellowing, a roaring," from past participle of Latin rugire "to bellow" (from PIE imitative root *reu-). If so, the notion is of the noise made by deer at the time of sexual excitement. The noun rut "roar of the sea" (1630s) in Scottish and persisting in New England dialect is of uncertain connection.
common toad of western and north-central Europe (rare in Britain) with a yellow stripe on its back, a distinctive running gait, and a loud mating call, 1769; the second element probably is the proper name jack (q.v.); for first element, Weekley suggests connection with attor "poison" (see attercop); it also could be echoic of its croaking.
type of venomous 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.
European bird noted for its love-note cry and notorious for parasitism, c. 1300, cokkou (late 12c. as a surname), from Old French cocu "cuckoo," also "cuckold," echoic of the male bird's mating cry (compare Greek kokkyx, Latin cuculus, Middle Irish cuach, Sanskrit kokilas).
Slang adjectival sense of "crazy" is American English, 1918, but noun meaning "stupid person" is recorded by 1580s, perhaps from the bird's unvarying, oft-repeated call. The Old English name was ʒeac, cognate with Old Norse gaukr, source of Scottish and northern English gowk, which also has insulting senses. The Germanic words presumably originally were echoic, too, but had drifted in form. Cuckoo-clock is from 1789.