The term that means that a material can be decomposed by natural means is "biodegradable." This refers to materials that can be broken down into smaller, simpler substances by microorganisms such as bacteria, fungi, and protozoa. Biodegradable materials are important because they can be recycled back into the environment without causing pollution or damaging ecosystems. Examples of biodegradable materials include food waste, paper products, and certain types of plastics made from natural materials.