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.
Some abbreviation of Gary's speech was necessary because he didn't have enough time to deliver all of it.2. Letters which are used to represent shortened forms or references to words or phrases: U.S.A., FBI, Calif., and Dr. are just a few abbreviations or shortened forms of words or phrases to represent the full terms.
3. Letters that are shortened references for a word or a phrase and which themselves are pronounceable as words: NATO, NASA, and UNICEF are types of abbreviations called acronyms; or abbreviations that may be pronounced as a word rather than just as a series of letters.
Remember: an abbreviation is pronounced as separate letters (U.S.A., FBI) while an acronym may be pronounced as a word (NATO, NASA).4. Etymology: from Middle French abréviation, from Late Latin abbreviationem, abbreviatio, from abbreviare "to make brief" from Latin ad, "to" + breviare "to shorten" from brevis "short, low, little, shallow".