Leaf mould is a nutrient-rich soil amendment that is created by composting fallen leaves. There are several synonyms for this term that are commonly used in gardening and landscaping. One of the most common synonyms is leaf litter, which refers to the layer of fallen leaves that accumulates on the ground in forests and natural areas. Another common synonym is humus, which is a term used to describe decomposed organic material that is rich in nutrients and beneficial to plant growth. Other synonyms for leaf mould include leaf compost, leaf debris, and leaf mulch. All of these terms describe the same type of organic material that is an excellent addition to any garden or landscaping project.