waste matter is a noun meaning "any materials unused and rejected as worthless or unwanted". It carries one recorded sense.
any materials unused and rejected as worthless or unwanted
“they collect the waste once a week”
“much of the waste material is carried off in the sewers”
Definitions, synonyms and semantic relations for waste matter come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.