Fixed oil, commonly known as carrier oil or vegetable oil, is a term used to refer to oils that are derived from plants and are non-volatile. These oils are widely used in the cosmetics and food industry due to their various benefits. Some common types of fixed oils are coconut oil, almond oil, olive oil, and jojoba oil. However, there are several synonyms for fixed oil that are less commonly used. These include base oil, fatty oil, unctuous oil, oleaginous oil, and lipid oil. Each of these synonyms emphasizes the oily nature of fixed oils and their importance in various fields.