1. A combining or blending of two or more substances without a chemical reaction; so, that the properties of the components are retained.
2. A combination of two or more different items, things, people, qualities, or substances.
3. An aggregate of two or more substances that are not chemically united and which exist in no fixed proportion to each other.
4. In construction, the assembled, blended, co-mingled ingredients of mortar, concrete, etc.; or the proportions for their assembly.
5. In pharmacology, a liquid medicine prepared by adding insoluble substances to a liquid medium, usually with a suspending agent.
6. In chemistry, a substance consisting of two or more substances combined; however, not in fixed proportions and not with chemical bonding.

A mixture is distinguished from a compound, which is formed by the chemical combination of two or more pure substances in a fixed, definite proportion.

The components of a mixture retain their own chemical properties and may be present in any proportion.

A mixture or combination of alcohol, chloroform, and ether; formerly used as an inhalation anesthetic.

A pharmaceutical mixture that is prepared a the time ordered from a prescription, rather than from something previously mixed.

An air-fuel combination that has a relatively high proportion of fuel and a relatively low quantity of air: In this case, rich mixture applies to oil and gas, or combustible fuel which exceeds the optimum level for such compositions or blends.