The word Peg Tantrum was chiefly used in the phrase to go to Peg Trantum’s and variants, meaning to go to one’s death.

This word is perhaps from Peg, rhyming form of Meg, pet form of the female forenames Margery and Margaret, and the noun tantrum—although it is first recorded a few years later.

Peg Tantrum is first attested in The fifth book of The works of Francis Rabelais, M.D. (London, 1694), the translation by Peter Anthony Motteux (1663-1718) of Le cinquiesme et dernier livre des faicts et dicts heroïques du bon Pantragruel (1564), by the French satirist François Rabelais (circa 1494-1553):

Do you see that Basin yonder in his Cage? Out of it shall sally Thunderbolts and Lightnings, Storms, Bulls, and the Devil and all, that will sink you down to Peg-Trantums an hundred Fathom under ground.

No similar term appears in the original French (Motteux also added bulls):

Voyez vous là dedans sa cage vn bassin? D’iceluy sortira foudre, tonnoirre, esclairs, diables & tempeste: par lesquels en vn moment serez cent pieds souz terre abismez.
     literal translation:
Do you see over there inside its cage a basin? Out of it shall come out lightning, thunder, thunderbolts, devils and storm: by which in a moment you will be a hundred feet underground sunk.

The phrase was recorded in A New Dictionary of the Terms Ancient and Modern of the Canting Crew (London, 1699), by “B. E. Gent.”:

Gon [sic] to Pegtrantums, Dead.

The British satirist Edward Ward (1667-1731) punned on the phrase in the chapter titled The Character of a Sea-Captain of The Wooden World dissected, in the Character of a Ship of War (London, 1709):

(3^rd edition – London, 1744)
He fulfils to a Tittle the never-failing Proverb, Set a Beggar on Horseback, and he’ll ride to Peg Crancums; for being once mounted his wooden Steed, there’s no stopping his Career, for he makes every Thing sheer before him.

The author played on the proverb set a beggar on horseback and he’ll ride to the Devil, meaning that someone unaccustomed to power or luxury will be corrupted by it, on the phrase to go to Peg-Tantrum’s and on the word crankums, denoting a sexually transmitted disease.

Robert Forby (1759-1825) recorded Peg-Tantrum in a different sense in The Vocabulary of East Anglia (London, 1830):

PEG-TRANTUM, a galloping, rantipole girl; a hoydenish mauther. Tranty occurs in R. N. C.* as applied to a child wise and forward above his age. Whatever may be the meaning of the word trant; in whatever language it may exist; it may have given origin to both these words. Our hoyden must be conceived to be strong and forward, though not wise above her age. Why she is called Peg, it is impossible to conjecture.

* R. N. C.: Ray’s North Country Words, i.e. A Collection of English Words not generally used, with their Significations and Original, in two Alphabetical Catalogues, the one of such as are proper to the Northern, the other to the Southern Counties (London, 1691), by the English naturalist and theologian John Ray (1627-1705)