Of, relating to, being, or affecting only a part; not total; incomplete: The plan calls for partial deployment of missiles. The police have only a partial description of the suspect. Favoring one person or side over another or others; biased or prejudiced: a decision that was partial to the plaintiff. Having a particular liking or fondness for something or someone: partial to spicy food. Mathematics Of or being operations or sequences of operations, such as differentiation and integration, when applied to only one of several variables at a time. Music See harmonic. Mathematics A partial derivative.