now obsolete, but a common oath in the Middle Ages and after, mid-14c., a corruption of the name of the Virgin Mary. It could mean "indeed, forsooth," be a term of asseveration, or be used to express surprise or any other feeling.
"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."
