ex·pres·sion

noun /ikˈspreSHən/ 
expressions, plural

1. The process of making known one's thoughts or feelings
- his views found expression in his moral sermons
- she accepted his expressions of sympathy

2. The conveying of opinions publicly without interference by the government
- the right to freedom of expression

3. The look on someone's face that conveys a particular emotion
- a sad expression

4. The ability to put an emotion into words
- envious beyond expression

5. A word or phrase, esp. an idiomatic one, used to convey an idea
- nowhere is the expression “garbage in, garbage out” any truer

6. The style or phrasing of written or spoken words
- subtlety of expression

7. The conveying of feeling in the face or voice, in a work of art, or in the performance of a piece of music
- eyes empty of expression
- their instruments have a rich variety of expression

8. A collection of symbols that jointly express a quantity
- the expression for the circumference of a circle is 2πr

9. The appearance in a phenotype of a characteristic or effect attributed to a particular gene

10. The process by which possession of a gene leads to the appearance in the phenotype of the corresponding character

11. The production of something, esp. by pressing or squeezing it out
- essential oils obtained by distillation or expression