Definition:Formula


 * A word or other collation in a formal language
 * A well-formed formula: a word approved of by a formal grammar
 * A logical formula: a well-formed formula in the context of symbolic logic
 * Another word for a propositional function.

Linguistic Note
The plural of formula is usually given nowadays as formulas, but the Classical plural formulae (or even formulæ) is frequently seen, particularly in older literature.