The prefix aqua- refers to water in its various states, such as liquid or gas. Some synonyms for this prefix include hydro-, which is also related to water, and lympha-, which relates to the lymphatic system. Other synonyms may include marine-, which is specific to the sea, and aqueous, which can refer to a solution made with water. The prefix can also be seen in various chemical compounds, such as aquamarine and aquaculture, which refer to the cultivation of aquatic organisms. Whatever the reference, the prefix aqua- is a common and useful tool for describing water-related concepts.