noun

1. an introducing or being introduced
2. anything introduced, or brought into use, knowledge, or fashion
3. anything that introduces, or prepares the way for; specif.,
   1. the preliminary section of a book, often having material considered essential to an understanding of the main text
   2. the preliminary part of a speech, treatise, etc.
   3. an opening section of a musical composition
   4. a preliminary guide or text
4. the formal presentation of one person to another, to an audience, to society, etc.

Etymology: ME introduccion < MFr introduction < L introductio