Jilt. From the Scottish gillet, a giddy young woman. This word expressed the diminutive of Jill or Julia, a name used in a contemptuous sense after Julia, the daughter of Augustus Cæsar, who disgraced herself by her dissolute conduct.

Jimmy. A crowbar used by house burglars. The word is not so much thieves’ slang as a corruption of Jenny, expressing the diminutive of gin or engine, the general term formerly for a machine or mechanical appliance.

Jimpson Weed. Properly “Jamestown Weed,” from the place in Virginia where it was introduced.

Jingo. See “[By Jingo].”

Jingoes. The British war party during the Russo-Turkish struggle of 1877-8, when there was grave likelihood of this country interfering. The term became popular through the refrain in G. H. Macdermott’s famous song:

“We don’t want to fight, but, by Jingo, if we do,

We’ve got the ships, we’ve got the men, we’ve got the money too.”

For a time the Jingo Party was in the ascendant.

Joachims-Thaler. See “[Thaler].”

Jockey. The diminutive of Jock, which is the Scottish form of Jack or John, expressive of a servant. The first jockeys engaged in horse racing were boys, on account of their light weight; hence the term.