An active submarine volcano on the Caribbean Sea floor, located 8 km (5 mi) north of the island of Grenada, or the strait where it lies.
1841, The Nautical Magazine[1], volume 10, page 601:
Even then, if she cannot lie S.E.b.S. at least, her reaching them will be very doubtful, and her best way will be to go through the passage between Kick-'em-Jenny and Carriacou, in order to weather Grenada before she gets into the strong lee current which prevails between that island and Trinidad, and renders it very difficult for ships to fetch Point Saline from the Bocas.
2009, Rosemary G. Gillespie, Encyclopedia of Islands[2], page 34:
The 12 submarine eruptions from Kick 'em Jenny are believed to have been dominantly explosive, although in at least one case a lava dome was extruded.
On the way, I learn from a feisty Jamaican writer that the turbulence one experiences, and to which Marshall gives epic meaning, is actually the result of volcanic action that is producing another island (affectionately called “Kick 'em Jenny”).
Kick 'em Jenny on Wikipedia.Wikipedia 