Definitionen
1.NounAn abbreviation formed by the initial letters of other words.
2.NounGenerally such abbreviations, including those pronounced as individual letters (initialisms such as "TNT").
3.NounExclusively such abbreviations when pronounced as a word (as "laser" or "NATO").
4.NounAn abbreviation formed by the beginning letters or syllables of other words (as "Benelux").
5.VerbTo form into an acronym.