An acronym is a word or name formed as an abbreviation from the initial components in a phrase or a word, usually individual letters (as in NATO- North Atlantic Treaty Organisation) and sometimes syllables (as in Benelux).

There are no universal standards of the multiple names for such abbreviations and of their orthographic styling. In English and most other languages, such abbreviations historically had limited use, but they became much more common in the 20th century. Acronyms are a type of word formation process, and they are viewed as a subtype of blending.

Although the word acronym is often used to refer to any abbreviation formed from initial letters, some dictionaries and usage commentators define acronym to mean an abbreviation that is pronounced as a word,in contrast to an initialism (or alphabetism)—an abbreviation formed from a string of initials (and possibly pronounced as individual letters).