by Jove

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1. •
   (UK, old-fashioned) minced oath for by God, Jove referring to Jupiter.

   • By Jove, I always took three threes for nine. — 1623
2. •
   (no longer used) Invocation of the Roman god Jupiter.

   • By Jove, master marchant, by sea or by land / Would get but smale argent if I did not stand / His very good master, I may say to you, / When he hazards in hope what hap will insue. — 1575