1. A word, formed from the first letters of a group of words, of which most people are unaware of what the original meaning of the word is, such as "laser" and "radar": The computer term "URL" (Uniform Resource Locator) is used on the internet as a website address, which has become an anacronym because very few people know what the letters stand for.
2. Etymology: said to be a combination of parts of the words anachronistic and acronym.