The area of a slaughterhouse where carcasses unfit for human consumption or other purposes are rendered down to produce useful materials such as glue.
A (notional) place to send a person or object that is spent beyond all reasonable use.
Overburden: waste material generated while searching for minerals or while mining, such as when sinking a shaft.
Rubbish, waste matter.
Tailings: waste rock from which the wanted gold, minerals, opal, etc., has been extracted.
Nonsense, rubbish.
A mess; the result of a blunder.
To clear waste material out of a mine.