milkmaid n.

"opaque white fluid secreted by mammary glands of female mammals, suited to the nourishment of their young," Middle English milk, from Old English meoluc (West Saxon), milc (Anglian), from Proto-Germanic *meluk- "milk" (source also of Old Norse mjolk, Old Frisian melok, Old Saxon miluk, Dutch melk, Old High German miluh, German Milch, Gothic miluks), from *melk- "to milk," from PIE root *melg- "to wipe, to rub off," also "to stroke; to milk," in reference to the hand motion involved in milking an animal. Old Church Slavonic noun meleko (Russian moloko, Czech mleko) is considered to be adopted from Germanic.

Of milk-like plant juices or saps from c. 1200. Milk chocolate (eating chocolate made with milk solids, paler and sweeter) is recorded by 1723; milk shake was used from 1889 for a variety of concoctions, but the modern version (composed of milk, flavoring, etc., mixed by shaking) is from the 1930s. Milk tooth (1727) uses the word in its figurative sense "period of infancy," attested from 17c. To cry over spilt milk (representing anything which, once misused, cannot be recovered) is first attested 1836 in writing of Canadian humorist Thomas C. Haliburton. Milk and honey is from the Old Testament phrase describing the richness of the Promised Land (Numbers xvi.13, Old English meolc and hunie). Milk of human kindness is from "Macbeth" (1605).

c. 1200 (late 12c. in place names and surnames), "an unmarried woman (usually young); the Virgin Mary;" shortening of maiden (n.). Like that word, used in Middle English of unmarried men as well as women (as in maiden-man, c. 1200, which was used of both sexes, reflecting also the generic use of man).

From c. 1300 as "a virgin," also as "maidservant, female attendant, lady in waiting." By c. 1500 this had yielded the humbler sense of "female servant or attendant charged with domestic duties." Often with a qualifying word (housemaid, chambermaid, etc.); maid of all work "female servant who performs general housework" is by 1790.

Her Mamma was a famous Fryer of Fishes,

Squeezer of Mops, Washer of Dishes,

From tossing of Pancakes would not Shirk,

In English plain, a Maid of all Work.

But don't mistake me, by Divinity,

When I mention Maid, I don't mean Virginity 

[from "Countess of Fame and her Trumpeter," 1793]

In reference to Joan of Arc, attested from 1540s (French la Pucelle). Maid Marian, the Queen of the May in the morris dances, also one of Robin Hood's companions, is recorded by 1520s, perhaps from French, where Robin et Marian have been stock names for country lovers since 13c. Maid of Honor (1580s) originally was "unmarried lady of noble birth who attends a queen or princess;" meaning "principal bridesmaid" is attested from 1895. Maydelond (translating Latin terra feminarum) was "the land of the Amazons."