Sorry for the necro. I find this immensely interesting, and have done some deep digging and made a video about the topic:
The earliest source I found is from a 1980 arcade operating manual of Space Panic, mentioning bosses. Another enemy in that game is a 'don'.
In early 1980's Japan, "bosu" (loanword from English) had a derogatory connotation to do with Mafia. Translating "bosu" would give you "boss", but in English the negative meaning is not present.
Old Kung Fu films use this term for mobsters too (Bruce Lee in The Big Boss).
~ GeoKoer
There's not really a "genre label" for this kind of gaming, simply because non-interactive games aren't much of a game genre. Most of the ones that exist are either silly idling games (Idle RPG/Progress Quest/Idle 2), bots (like this one that plays a roguelike by itself), or more AI experiment than game (Conway's Game of Life, for instance).
I think that "Zero Player Games" or "bot game" is about the best you can do. I did find some interesting articles when I searched for "games that play themselves."
There's also a subgenre of the strategy genre where you'll find games where you can only interact indirectly with the game world, with games like Populous or Evil Genius. This subgenre is generally called "Artificial Life" or "God Game".
Some games are capable of playing themselves, in a demo or "attract" mode. Arcade games are especially fond of this, as it attracts people to the cabinet and shows them what they might get for dropping in a quarter.
If we consider things like ProgressQuest games, then screensavers might be considered non-interactive games as well (or in reverse, non-interactive games might be screensavers). There was one screensaver for Win95 that played a little maze, for instance. Of course, there's also the iconic After Dark package that not only featured a number of things you might consider to be non-interactive games, but also some screensavers that were fully playable, like Lunatic Fringe.
Part of the problem is that we already have many non-interactive forms of digital entertainment. We give them many terms, but one is "movie." You could consider a movie like Scott Pilgrim vs. The World to be a "game that plays itself." The protagonist even levels up, has extra lives, and fights a final boss. Or, take the movie Clue, which went so far as to include multiple endings, and each time you went to see it there was a chance you'd see a different one. (I realize that's tangential, but it's sort of an interesting aside to your question.)
"Non Games" is a similar term, but it's more for games that have no goal, like Mario Paint. These games ride the line between game and application.
Best Answer
As far as I am aware, the use of the term "clan" to refer to a group of players of a game was popularized by Quake.
Quake's multiplayer capabilities were pivotal to the nascent e-sports scene along the broadening availability of broadband internet, so it was one of (if not the) first FPS around which competitive and co-operative groups would form, communicate and self-identify on a scale that only the internet could foster.
The name likely came from Quake's gothic, medieval feel, although I can find no concrete information on who first coined the term. It has persisted as a common group moniker for FPS games since Quake itself was an FPS.
The concept of a calling a group of players something like a "clan" or "guild," however, is definitely older than Quake (references to guilds with "guild tags" can be found in Computer Gaming World back issues from the 1980s, specifically issue #29, in an article about Island of Kesmai, a CompuServe MUD).