Waste
This can be defined as “…any substance or object which the holder discards or intends or is required to discard;â€. (2008 Waste Framework Directive (Directive 2008/98/EC, Article 3(1)),
https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32008L0098&from=EN)
This can be categorised in various ways, although for grounds management the use of Inorganic waste and Organic waste as categories is appropriate.