Acronym (noun)

1. A word formed from the initial letters or groups of letters of other words.
2. An abbreviation formed from the initial letters of other words and pronounced as a word.

Origin:

From the greek words "akros" meaning "topmost" and "onuma" meaning "name".

Examples:

1. NASA is an acronym for National Aeronautics and Space Administration.
2. AIDS is an acronym for Acquired Immune Deficiency Syndrome.
3. The acronym NATO stands for North Atlantic Treaty Organization.
4. The acronym YOLO stands for You Only Live Once.
5. The acronym DARE stands for Drug Abuse Resistance Education.