Biodiversity is a term used to describe the variety of life on earth. However, there are several synonymous terms that can also be used to refer to this concept. One term that can be used alternatively is "biological diversity," which captures the range of living organisms and their relationships in an ecosystem. Another term is "ecological diversity," which highlights the diversity of ecosystems and habitats that exist on earth. Additionally, "species diversity" refers to the variety of different species that exist within a particular ecosystem. Overall, while biodiversity is the most commonly used term, there are multiple other similar terms that can also be applied to describe the importance and complexity of life on earth.