lunette

Lunette, a word borrowed from French, looks like it should mean "little moon"—luna being Latin for "moon" and -ette being a diminutive suffix. There is indeed some 17th-century evidence of the word being used for a small celestial moon, but that meaning is now obsolete. Earlier, in the 16th century, lunette referred to a horseshoe having only the front semicircular part—a meaning that still exists but is quite rare. Other senses of lunette that are infrequently used nowadays include "a blinder especially for a vicious horse" and, in the plural form, "spectacles." (Lunettes is the usual term for eyeglasses in modern French.) The oldest meaning of lunette still in common use is "something shaped like a crescent or half-moon," which our evidence dates to the early 1600s.