1680s, "pollute with menstrual blood" (transitive), a sense now rare or obsolete; 1752 as "to discharge the menses," probably a back-formation from menstruation, or else from Latin menstruatus, past participle of menstruare, from menstruus "monthly," from mensis "month" (see moon (n.)). Related: Menstruated; menstruating.
early 15c., "moonlight, the shining of the moon," from moon (n.) + shine (n.). Similar formation in Dutch maneschijn, German Mondschein, Swedish månsken, Danish maaneskin. In a figurative use, "appearance without substance, pretense, fiction" from late 15c.; perhaps from the notion of "moonshine in water" (see moonraker) or "light without heat."
Meaning "illicit or smuggled liquor" is attested from 1785 (earliest reference is to that smuggled on the coasts of Kent and Sussex; in reference to Southern U.S., by 1829), from the notion of being brought in or taken out under cover of darkness at night. Moonlight also occasionally was used in this sense early 19c. As a verb in this sense from 1883. Related: Moonshiner "smuggler; one who pursues a dangerous or illegal trade at night" (1860).
1827, "period or term of six months," specifically, a half-year course in a German or other Continental university, from German Semester "half-year course in a university," from Latin semestris, in cursus semestris "course of six months," from semestris, semenstris "of six months, lasting six months, half-yearly, semi-annual," from assimilated form of sex "six" (see six) + mensis "month" (see moon (n.)). The word, and the idea, were picked up in the U.S., where the German higher education system served as a model. Related: Semestral; semestrial (1701).
"one-twelfth part of a year; one of the twelve parts into which the calendar year is arbitrarily divided," Old English monað, from Proto-Germanic *menoth- (source also of Old Saxon manoth, Old Frisian monath, Middle Dutch manet, Dutch maand, Old High German manod, German Monat, Old Norse manaðr, Gothic menoþs "month"), which is related to *menon- "moon" (see moon (n.)). Originally the month was the interval between one new moon and the next (a sense attested from late Old English).
Its cognates mean only "month" in the Romance languages, but in Germanic they generally continue to do double duty. The development of the calendrical meaning for words from this root in Greek (mēn) and Latin (mensis) was accompanied by the creation of new words for "moon" (selēnē, luna). The phrase a month of Sundays "a very long time" is from 1832 (roughly 7 and a half months but never used literally).
1974, nickname for a member of the Unification Church, headed by Sun Myung Moon.
also moon-raker, "stupid or silly person," in England, a name traditionally given to Wiltshire people, 1787, from the stock joke about fools who mistook the reflection of the moon in a pond for a cheese and tried to rake it out. But as told in Wiltshire, the men were surprised trying to rake up kegs of smuggled brandy, and put off the revenuers by acting foolish. Compare moonshine. Related: Moonraking.
"student of the moon, one who occupies himself with study of the physiography of the moon," 1660s, from selenography "scientific study of the moon" (1640s), originally to map the landforms of it, from seleno-, combining form of Selene "moon" + -graphy. Selenograph "photograph of the surface of the moon" is by 1858. Related: Selenographic (by 1830 as a dictionary word);selenographical.