faeces vs faecal matter

faeces and faecal matter both are nouns.

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

As nouns, faeces and faecal matter are synonyms defined as:

faeces and faecal matter: solid excretory product evacuated from the bowels

Other synonyms of faeces include BM, dejection, fecal matter, feces, ordure, stool.

faeces (noun)	faecal matter (noun)
solid excretory product evacuated from the bowels	solid excretory product evacuated from the bowels