- The act of expressing, conveying, or representing in words, art, music, or movement; a manifestation: an expression of rural values.
- Something that expresses or communicates: Let this plaque serve as an expression of our esteem.
- Mathematics A symbol or combination of symbols that represents a quantity or a relationship between quantities.
- The manner in which one expresses oneself, especially in speaking, depicting, or performing.
- A particular word or phrase:"an old Yankee expression .. 'Stand up and be counted'"(Charles Kuralt).
- The outward manifestation of a mood or a disposition: My tears are an expression of my grief.
- Genetics The act or process of expressing a gene.