excrement: [16] Latin excrēmentum meant originally ‘that which is sifted out’ (it was a derivative of the verb excernere, a compound formed from the prefix ex- ‘out’ and cernere ‘sift, decide’, from which English gets certain). Hence it was applied metaphorically to any substance that is excreted from or secreted by the body, including sweat, nasal mucus, and milk, as well as faeces. (English acquired excrete [17], incidentally, from the past participle of excernere, excrētus.) This very general sense survived in English into the mid 18th century, when it was finally ousted by the more specific ‘faeces’. (Increment, by the way, is a completely unrelated word, coming ultimately from Latin crēscere ‘grow’.) => certain, crime, critic, discern, discriminate, secret
1530s, "waste discharged from the body," from Latin excrementum, from stem of excretus, past participle of excernere "to sift out, discharge," from ex- "out" (see ex-) + cernere "sift, separate" (see crisis). Originally any bodily secretion, especially from the bowels; exclusive sense of "feces" is since mid-18c. Related: Excremental; excrementitious.
