Decompose/ˌdiːkəmˈpəʊz/ Definition 1 of 4Pro Tip 1/2Natural Processes Used to describe how organisms or natural substances change over time. Leaves on the forest floor decompose and enrich the soil. Pro Tip 2/2Time Factor Emphasizes that the process happens gradually and can vary in speed. Food waste will decompose faster if it's exposed to heat.