1. The result of reducing something, such as a form or a short summary: The Executive Summary of the report was a good abbreviation of the full financial report.
2. A shortened form of a spoken word, or written symbol; a part of a word or symbol standing for the whole: There are many abbreviations for title words and one common abbreviation is Mr. for Mister.

A very familiar abbreviation is "etc." which is the abbreviation for "et cetera" meaning "and the rest", "and others", "and so forth" which is used at the end of a list to indicate that other items of the same class or type should be considered or included.