a solution able to absorb a certain quantity of acid or base without undergoing a strong variation in pH

a solution that has the capacity to resist change in pH (usually a decrease)

A solution that maintains a near constant pH for a system. An aqueous solution of either a weak acid or base and salt of the weak acid or base

A solution which has the ability to oppose changes in pH when small quantities of acid or base are added to it.

Solution that resists change in pH; contains either a weak acid and a soluble ionic salt of the acid or a weak base and a soluble ionic salt of the base.

a solution of definite pH made up in such a way that the pH alters only gradually with the addition of an acid or a base.

Buffer solutions are solutions which resist change in hydronium ion and the hydroxide ion concentration (and consequent p H) upon addition of small amounts of acid or base, or upon dilution. Buffer solutions consist of a weak acid and its conjugate base (more common) or a weak base and its conjugate acid (less common).