*tem-

late 14c., "study or knowledge of the structure and function of the human body" (learned by dissection); c. 1400, "anatomical structure," from Old French anatomie and directly from Late Latin anatomia, from late Greek anatomia for classical anatomē "dissection," literally "a cutting up," from ana "up" (see ana-) + temnein "to cut" (from PIE root *tem- "to cut").

"Dissection" (1540s), "mummy" (1580s), and "skeleton" (1590s) were primary senses of this word in Shakespeare's day; the meaning "the science of the structure of organized bodies" predominated from 17c. Of persons, "the body," from 1590s. Often misdivided as an atomy or a natomy (see N).

The scyence of the Nathomy is nedefull and necessarye to the Cyrurgyen [1541]

late 15c., as a hypothetical indivisible extremely minute body, the building block of the universe, from Latin atomus (especially in Lucretius) "indivisible particle," from Greek atomos "uncut, unhewn; indivisible," from a- "not" (see a- (3)) + tomos "a cutting," from temnein "to cut" (from PIE root *tem- "to cut").

An ancient term of philosophical speculation (in Leucippus, Democritus); revived scientifically 1805 by British chemist John Dalton. In late classical and medieval use also a unit of time, 22,560 to the hour. Atom bomb is from 1945 as both a noun and a verb; compare atomic.