■ noun
1》 the action of introducing or being introduced.
↘a thing, such as a product or plant, that is newly brought in.
2》 a formal presentation of one person to another, in which each is told the other's name.
3》 a preliminary thing, such as an explanatory section at the beginning of a book, report, etc.
↘a preliminary section in a piece of music.
4》 a book or course of study intended to introduce a subject to a person.
↘a person's first experience of a subject or thing.