faecal matter vs turd

faecal matter and turd both are nouns.

Word	Noun	Adjective	Verb	Adverb
faecal matter	Yes	No	No	No
turd	Yes	No	No	No

As nouns, turd is a hyponym of faecal matter; that is, turd is a word with a more specific, narrower meaning than faecal matter:

Other hyponyms of faecal matter include dog do, dog shit, dog turd, doggy do, crap, dirt, poop, shit, shite, droppings, dung, muck, meconium, melaena, melena.

faecal matter (noun)	turd (noun)
solid excretory product evacuated from the bowels	obscene terms for feces