1. an established form or set of words, as used in religious ceremonies, legal proceedings, etc.
2. (mathematics, physics a general relationship) , principle, or rule stated, often as an equation, in the form of symbols
3. (chemistry) . a representation of molecules, radicals, ions, etc., expressed in the symbols of the atoms of their constituent elements.
4. a method, pattern, or rule for doing or producing something, often one proved to be successful
a. a prescription for making up a medicine, baby's food, etc.
b. a substance prepared according to such a prescription6. (motor racing) . the specific category in which a particular type of car competes, judged according to engine size, weight, and fuel capacity