To make (something or someone) known by formal announcement or recommendation.
To cause (someone) to be acquainted (with someone else).
To add (something) to a system, a mixture, or a container.
To bring (something) into practice.
To introduce or make a comment before (the main point).
To give a preface to.
An introduction, or series of preliminary remarks.
A title or epithet.
The beginning or introductory portion that comes before the main text of a document or book.
The prelude or introduction to the canon of the Mass.