by Jupiter

English

From Latin pro Iuppiter. Ellipsis of a full oath of the form "I swear by Jupiter that…". Originally a literal oath; later a minced oath.

(obsolete, Classics) Invocation of the Roman god Jupiter.
- 1820 [423 BC], “The Clouds”, in Thomas Mitchell, transl., The Comedies of Aristophanes, volume 1, translation of Νεφέλαι Nephelai by Aristophanes, page 91:
  I see how it is with you. You are mad, / Stark mad, by Jupiter!
(dated, chiefly British) Minced oath for by God.
- c. 1603–1606, William Shakespeare, King Lear, act 1, scene 1, lines 178–179:
  Away! By Jupiter, / This shall not be revoked!
- 1874 September, Fannie Hodgson Burnett, “Pretty Polly Pemberton”, in Peterson's Magazine, volume 66, number 3, page 180:
  "By Jupiter!" employing his usual mild expletive, "look here, old fellow, had she a white dress on, and geranium-colored bows, and—"