atomy
A skeleton.
archaic
Poor Brother Tom had an Accident this time Tvvelve-month, and ſo clever a made Fellovv he vvas, that I could not ſave him from thoſe fleaing Raſcals the Surgeons; and novv, poor Man, he is among the Otamys at Surgeon's Hall.
A person who is very emaciated or thin; a skeleton.
figuratively
Hoſt[ess, i.e., Mistress Quickly]. I [aye] come, you ſtarude blood-hound. / VVhoore [Doll Tearsheet]. Goodman death, goodman bones. / Hoſt. Thou Atomy, thou. / VVhoore. Come you thinne thing, come you raſcall.
Chiefly in the works of the English author Charles Dickens (1812–1870): a thing which is very slender and weak.
figuratively, obsolete
[T]he contents of his plate chest, consisting of two withered atomies of teaspoons, and an obsolete pair of knock-knee'd sugar tongs; […]
Where it comes from
Rebracketing of anatomy (“skeleton”) as an atomy; compare notomy.
Adapted from the Wiktionary entry atomy (CC BY-SA 4.0).