fecal (adj.)

also faeces, c. 1400, "dregs," from Latin faeces "sediment, dregs," plural of faex (genitive faecis) "grounds, sediment, wine-lees, dregs," which is 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."

suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).

see fecal.