Expression (noun)

1. The act of expressing something or the way in which something is expressed.
2. A word, phrase, or symbol that represents a specific quantity, meaning, or idea.
3. A particular way of saying something.
4. An indication of a person's thoughts, feelings, or mood.
5. The use of art or other mediums to convey an idea or feeling.

Origin:

Late middle english: from latin expressio(n-), from express- "pressed out", from the verb exprimere (see express).

Examples:

1. He had a unique expression.
2. She had an expression of joy on her face.
3. The expression of love in the poem is beautiful.
4. The artist used different colors to express emotions.
5. The algebraic expression represents a mathematical relationship.