1640s, "purification of the mind or soul" (figurative); 1650s, "act or process of separating from lees or dregs, a cleansing from impurities," from Late Latin defecationem (nominative deficatio), noun of action from past-participle stem of Latin defaecare "cleanse from dregs, purify," from the phrase de faece "from dregs" (see de- + feces). Meaning "act of evacuating the bowels" is from 1830. An Old English word for "bowel movement" was arse-gang literally "arse-going."
also kaka-, Proto-Indo-European root meaning "to defecate." According to Watkins, "imitative of glottal closure during defecation."
It is the hypothetical source of/evidence for its existence is provided by: Greek kakke "human excrement," Latin cacare, Irish caccaim, Serbo-Croatian kakati, Armenian k'akor; Old English cac-hus "latrine."
Etymologists dispute whether the modern Germanic words (Dutch kakken, Danish kakke, German kacken), are native cognates or student slang borrowed from Latin cacare. Caca appears in Modern English in slang c. 1870, and could have been taken from any or several of the languages that used it.
c. 1300, "sum, aggregate of a collection," from Anglo-French noumbre, Old French nombre and directly from Latin numerus "a number, quantity," from PIE root *nem- "assign, allot; take."
Meaning "written symbol or figure of arithmetic value" is from late 14c. Meaning "single (numbered) issue of a magazine" is from 1795. Colloquial sense of "a person or thing" is by 1894. Meaning "dialing combination to reach a particular telephone receiver" is from 1879; hence wrong number (1886). The modern meaning "musical selection" (1885) is from vaudeville theater programs, where acts were marked by a number. Earlier numbers meant "metrical sound or utterance, measured or harmonic expression" (late 15c.) and, from 1580s, "poetical measure, poetry, verse."
Number one "oneself" is from 1704 (mock-Italian form numero uno attested from 1973); the biblical Book of Numbers (c. 1400, Latin Numeri, Greek Arithmoi) is so called because it begins with a census of the Israelites. Childish slang number one and number two for "urination" and "defecation" attested from 1902. Number cruncher is 1966, of machines; 1971 of persons. To get or have (someone's) number "have someone figured out" is attested from 1853; to say one's number is up (1806) meaning "one's time has come" is a reference to the numbers on a lottery, draft, etc. The numbers "illegal lottery" is from 1897, American English.
"to defecate," 1846, from a cluster of older nouns, now dialectal or obsolete, applied to things cast off or discarded (such as "weeds growing among corn" (early 15c.), "residue from renderings" (late 15c.), underworld slang for "money" (18c.), and in Shropshire, "dregs of beer or ale"), all probably from Middle English crappe "grain that was trodden underfoot in a barn, chaff" (mid-15c.), from French crape "siftings," from Old French crappe, from Medieval Latin crappa, crapinum "chaff." Related: Crapped; crapping.
For connection of the idea of defecation with that of shedding or casting off from the body, compare shit (v.). Despite the etymological legend, the word is not from the name of Thomas Crapper (1837-1910) who was, however, a busy plumber and may have had some minor role in the development of modern toilets. The name Crapper is a northern form of Cropper (attested from 1221), an occupational surname, obviously, but the exact reference is unclear. Crap (v.) as a variant of crop (v.) was noted early 19c, as a peculiarity of speech in Scotland and what was then the U.S. Southwest (Arkansas, etc.).
Draw out yere sword, thou vile South'ron!
Red wat wi' blude o' my kin!
That sword it crapped the bonniest flower
E'er lifted its head to the sun!
[Allan Cunningham (1784-1842), "The Young Maxwell"]