feces (n.) Look up feces at Dictionary.com
also faeces, c.1400, "dregs," from Latin faeces "sediment, dregs," plural of faex (genitive faecis) "grounds, sediment, wine-lees, dregs," of unknown origin. Specific sense of "human excrement" is from 1630s in English but is not found in classical Latin. Hence Latin faex populi "the dregs of the people; the lowest class of society."