Acronym, abbreviation formed from the initial letter or group of letters of two or more words . The term dates to the 1940s and derives from the Greek words akros, meaning “topmost” or “highest,” and onyma, meaning “name” or “word.” Acronym definition: a word formed from the initial letters or groups of letters of words in a set phrase or series of words and pronounced as a separate word, as Wac from Women's Army Corps, OPEC from Organization of Petroleum Exporting Countries, or loran from long-range navigation.. Find out what any acronym , abbreviation , or initialism stands for With more than 1,000,000 human-edited definitions, Acronym Finder is the world's largest and most comprehensive dictionary of acronyms , abbreviations , and initialisms. Combined with the Acronym Attic, Acronym Finder contains more than 5 million acronyms and abbreviations . What Is an Acronym? – Meaning and Definition An acronym is a short word formed by the combination of the first letters of words representing the name of something. The Oxford English Dictionary defines the term ‘ acronym ’ as “a word formed from the initial letters of other words or (occasionally) from the initial parts of syllables taken from other words, the whole being pronounced as a single word”. According to the Merriam-Webster Dictionary, an acronym is defined as “a word ...