"shallow, flat vessel containing hot water in which another vessel is placed to heat its contents gently," by 1733 (in a cookery book, earlier, 1724 as the name of a meat dish cooked in one), from French bain-marie, from Medieval Latin balneum Mariae, literally "bath of Mary."

According to French sources, perhaps so called for the gentleness of its heating; others credit the name to the supposed inventor, Mary the Jewess, mentioned in early gnostic writings and looked on since 4c. C.E. as a founder of alchemy. Middle English had balne of mary (late 15c.). French bain was used by itself in English in various sense 15c.-17c.; it is from baigner "to bathe" (12c.), from Latin balneare, from balneum "bath" (see balneal).

late 14c., marybones (late 13c. as a surname), "bone containing fat or marrow," from marrow + bone (n.). A poetic Old English word for "bone" was mearhcofa "marrow-chamber." Later generally of any large bone. The conjecture that it is a corruption of Mary-bones, in allusion to the reverence paid to the Virgin Mary by kneeling "is absurd" [Century Dictionary]; nonetheless, marrowbones is used especially to mean "the bones of the knees" (1530s). To ride in the marrow-bone coach was one of many terms in old slang for "to go on foot."

1580s, Italian title of address or courtesy, equivalent to madam; from c. 1600 as a noun, "an Italian lady," from Italian madonna, from Old Italian ma donna (Italian mia donna) "my lady," from ma "my" + donna "lady," from Latin domina "lady, mistress of the house," from Latin domus "house" (from PIE root *dem- "house, household").

Often specifically "the Virgin Mary," hence the sense of "picture or statue of the Virgin Mary," attested in English by 1640s. The U.S. singer/dancer (full name Madonna Louise Ciccone, b. 1958) attained to pop stardom in the fall of 1984.

fem. proper name, from Spanish Maria de los Dolores, literally "Mary of the Sorrows," from plural of dolor, from Latin dolor "pain, sorrow," perhaps from PIE root *delh- "to chop" "under the assumption than 'pain' was expressed by the feeling of 'being torn apart'" [de Vaan]. 

"a pearl," late Old English, from Late Latin margarita (see Margaret). Figuratively, "that which is precious or excellent, a priceless quality or attribute;" also used as an epithet for Christ, Mary, etc., late 13c. Also margerie (mid-14c.). Related: Margaritic.

fem. proper name, from French, a variant of Marian; sometimes Englished as Mary Anne. It was the name of a republican secret society formed in France in 1851, when it became the designation of the female figure of "liberty" popular since the days of the Revolution; hence "personification of the French Republic" (1870).