Macronym: An acronym composed of acronyms. I invented this word around 1990 in reposnse to the use of the acronym, "PISB". PISB was used in an online bulletin board by contributors when referring to the bulletin board. For example, "Did you read that post that Ira left on PISB last night?" The name of the board was PACS IBM SIG BBS, or PISB for short. As you can see, the "words" that make up the acronym are themselve acronyms. They stand for Philadelphia Area Computer Society, International Business Machine Special Interest Group Bulletin Board System. I thought that "macronym" was especially appropriate as it described a term (PISB) used by computer enthusiasts.