"in the matter of, in the (legal) case of," c. 1600, probably from Duns Scotus; Latin, from re, ablative of res "property, goods; matter, thing, affair," from Proto-Italic *re-, from PIE *reh-i- "wealth, goods" (source also of Sanskrit rayi- "property, goods," Avestan raii-i- "wealth").
slang phrase meaning, more or less, "I don't care, I don't worry," 1913, of unknown origin, but perhaps derived from Yiddish nisht gefidlt. Said to have been popularized by comedienne Fanny Brice (1891-1951), but earliest references do not mention her.
Chicken pox doesn't poison the wellsprings of one's existence like 'Ish kabibble,' and 'I should worry.!' Do you think it's any fun to bring up children to speak decent English, and then have their conversation strewed with phrases like that and with ain'ts? Do you think I like to hear Robert talking about his little friends as 'de guys' and 'de ginks?' [Mary Heaton Vorse, "Their Little Friends," in Woman's Home Companion, February 1916]
Latin phrase, literally "I think, therefore I am;" the starting point of Cartesian philosophy (see Cartesian), from cogito, first person singular present indicative active of cogitare "to think" (see cogitation) + ergo "therefore" (see ergo) + sum, first person singular present indicative of esse "to be" (from PIE root *es- "to be").
Latin expression meaning "I am to blame, through my own fault," a phrase from the prayer of confession in the Latin liturgy. For culpa, see culpable.
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).