—v.t. 1. to change or alter, as in form, appearance, character, or substance: to vary one's methods. 2. to cause to be different from something else: The orchestra varied last night's program with one new selection. 3. to avoid or relieve from uniformity or monotony; diversify: to vary one's diet. 4. Music.to alter (a melody or theme) by modification or embellishments without changing its identity.
—v.i. 1. to show diversity; be different: The age at which children are ready to read varies. 2. to undergo change in appearance, form, substance, character, etc.: The landscape begins to vary as one drives south. 3. to change periodically or in succession; differ or alternate: Demand for certain products varies with the season. 4. to diverge; depart; deviate (usually fol. by from): to vary from the norm. 5. Math.to be subject to change.
6. Biol.to exhibit variation.