also hotdog, "sausage on a split roll," c. 1890, American English, from hot (adj.) + dog (n.). Many early references are in college student publications; later popularized, but probably not coined, by cartoonist T.A. "Tad" Dorgan (1877-1929). It is said in early explanations to echo a suspicion (occasionally justified) that sausages contained dog meat.
Meaning "someone particularly skilled or excellent" (with overtones of showing off) is from 1896. Connection between the two senses, if any, is unclear. Hot dog! as an exclamation of approval was in use by 1906.
hot-dog, n. 1. One very proficient in certain things. 2. A hot sausage. 3. A hard student. 4. A conceited person. ["College Words and Phrases," in Dialect Notes, 1900]
Related: Hot-dogger; hot-dogging.
"period of dry, hot weather at the height of summer," 1530s, from Latin dies caniculares, the idea, though not the phrase, from Greek; so called because they occur around the time of the heliacal rising of Sirius, the Dog Star (kyōn seirios). Noted as the hottest and most unwholesome time of the year; often reckoned as July 3 to August 11, but variously calculated, depending on latitude and on whether the greater Dog-star (Sirius) or the lesser one (Procyon) is reckoned.
The heliacal rising of Sirius has shifted down the calendar with the precession of the equinoxes; in ancient Egypt c. 3000 B.C.E. it coincided with the summer solstice, which also was the new year and the beginning of the inundation of the Nile. The "dog" association apparently began here (the star's hieroglyph was a dog), but the reasons for it are now obscure.
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]
childish deformed language (there are many different versions), by 1889 (hog Latin in same sense is attested by 1807).
The animals play quite an important part in the naming [of children's languages], as the hog, dog, fly, goose, pigeon, pig, all give names, with Mr. Hog leading. Among the names the Latins take the lead, and Hog Latin leads the list, being accredited as naming nearly as many languages as all the other names combined. Besides Hog Latin, there is Dog Latin, Pig Latin, Goose Latin, and Bum Latin. Then there is Greekish and Peddlers' French and Pigeon English. ... Very few can give any reason for the naming of the languages. In fact, no one can fully say where the great majority of names came from, for in most cases in the naming the following pretty well expresses the difficulty: "It was born before I was. I can't tell how young I was when I first heard of it." ["The Secret Language of Children," in The North Western Monthly, October 1897]
For the language itself, compare loucherbem, a 20c. French slang similar to pig Latin, which takes its name from the form of the word boucher in that language (which is said to have originated among the Paris butchers).
in the figurative sense "wildly irresponsible person, potent person or thing freed from usual restraint," by 1896; in the literal sense an object of dread on old warships; the figurative use probably arose from a celebrated scene in a popular late novel by Victor Hugo:
You can reason with a bull dog, astonish a bull, fascinate a boa, frighten a tiger, soften a lion; no resource with such a monster as a loose cannon. You cannot kill it, it is dead; and at the same time it lives. It lives with a sinister life which comes from the infinite. It is moved by the ship, which is moved by the sea, which is moved by the wind. This exterminator is a plaything. [Victor Hugo, "Ninety Three," 1874]