MEANING: noun:
1. Something imaginary.
2. Someone out of their element; a misfit.
3. A marine part of a cavalry or a cavalryman doing marine duty.

ETYMOLOGY: From horse, from Old English hors + marine, from Latin mare (sea). Earliest documented use: 1823.

NOTES: It sounds ridiculous that a soldier mounted on a horse would be of much use on water and that’s the idea behind the term horse marine. As unbelievable as it sounds, there have been horse marines in practice; there have been some famous horses in the US Marine Corps. Meet Staff Sergeant Reckless

HORSE FARINE - equine brought up eating only flour (thus poorly nourished and weak)

HORDE MARINE - an army (navy?) of Mermen

HORS DE MARINE - (French) blown out of the water