"ordinary dress of civil life" (as opposed to military uniform), 1822; in reference to police detectives, it is attested from 1842. Also plainclothes.
1714, as an adverb, "out of the ordinary," from French hors d'oeuvre, "outside the ordinary courses (of a meal)," literally "apart from the main work," from hors, variant of fors "outside" (from Latin foris; see foreign) + de "from" + oeuvre "work," from Latin opera (from PIE root *op- "to work, produce in abundance"). Meaning "extra dish set out before a meal or between courses" attested in English from 1742.
breed of domestic dog, originally used in police work, 1911 (as pincher Dobermann from 1907), named for Ludwig Dobermann, 19c. German dog-breeder in Thuringia. Pinscher "fox terrier" seems to be a 19c. borrowing from English pinch (see Kluge).
Der Kutscher aus gutem Hause verschafft sich, wie er kann und wenn er kann, einen ganz kleinen englischen Pinscher, der den Pferden sehr gut gut folgt und die großen Dänen von ehedem ersetzt hat, aus J.J. Rousseau's Zeit, der von dem dänischen Hunde umgerannt wurde, wie ihr wißt. ["Paris, oder, Das Buch der Hundert und Ein," Volume 6, Theodor Hell (pseud.), Potsdam, 1833]
"intense interrogation by police," 1900, probably a reference to Third Degree of master mason in Freemasonry (1772), the conferring of which included an interrogation ceremony. Third degree as a measure of severity of burns (most severe) is attested from 1866, from French (1832); in American English, as a definition of the seriousness of a particular type of crime (the least serious type) it is recorded from 1865.
"police informer," 1859, American English; earlier "one who betrays the unwary (or is used to betray them)," 1821, originally a decoy bird (1812); said to be from decoys being fastened to stools to lure other pigeons. But perhaps related to stall "decoy bird" (c. 1500), especially "a pigeon used to entice a hawk into the net" (see stall (n.2)). Also see pigeon.
common name for auricula, 1825, so called from the powder on the leaves and flower; millers, by the nature of their work, being famously dusty.
"dense forest in an area of high rainfall with little seasonal variation," 1899, apparently a loan-translation of German Regenwald, coined by A.F.W. Schimper for his 1898 work "Pflanzengeographie."