No longer living organic material particularly that consists of chunks and that is neither nor colloidal.

Detritus thus is not whole orgranisms and not so small as to be potentially attacked simultaneously in its entirity by digestive enzymes, but instead is somewhere in the middle, hence "Chunks".

If it had been part of a larger organism and currently an animal can pick it up and move it to a new location prior to it, then it in all likelihood is detritus.

Prominently, detritus is consumed be detrivores, though also by decomposers.