Alright, well, this is my arguement in favor of the term Genocide Route. 

Genocide Route is the most widely used term by the community, and the wiki should be structured so that people can most easily find the information that they need. 

Toby Fox, the creator of Undertale, has used the term "Genocide Route," and did not appear to have an issue with it. He has no issue with the name, and doesn't mind if it's used.

It's claimed that the term was originally coined during this twitch livestream,  a playthrough in which the protagonist was named Hitler, and who apparently made multiple offensive jokes regarding the situation. I argue, that while this is perhaps not the best origin, the name has gained signifigant traction, and the wiki should reflect what most people consiter the name of this route. 

We can't simply make names up. While some names may be more fitting, or more witty, or less offensive, this is the name most widely used, and that fact cannot be ignored. 

The argument against this name is purely pathological: it's not based in fact, but emotional appeal. This wiki should primarily serve as a source for accurate information, not to appease to wishes of those that believe the term "Genocide" is offensive.

The term Genocide, while perhaps not the best term, per say, effectively demonstrates the severity and weight of the player's actions, and accurately reflects the game's commentary of video game protagonists systematicly annihilating countless enemies, with no real thought to them as anything other than game constructs.  

And this is my argument against the term Genocide Route.

The term should not be used simply because you claim it is more popular. First, do you have any evidence to back that up? The name of "No Mercy" is gaining a signifigant amount of traction within the community, and is probably equally popular at this point, although this claim cannot be accurately proven.

"If people care about using a word more than they care about people's feelings, those are the people you should say away from. Just saying, asking someone to use a different word is not that big a deal. Telling someone you don't care about their feelings and you're going to use that word anyways is a pretty jerk move. Kind of silly to be arguing this in a game that encourages you to build positive relationships with others." - anonymous user

Argument For: Toby has used the term himself, and it's already used significantly across the wiki on any pages that mention it. It's also a popular term in the fandom, even if No Mercy is also popular.

A lot of arguments against the use of the term are saying Toby requested people not use it which is a blatant lie, so...

I can understand the problems with the origin of the name, but the fact of the matter is, the route itself is a genocide of the characters in the game, not just showing No Mercy. It also provides a stark contrast to the True Pacifist and Neutral route names because this is the worst and most horrific route, as implied by the Genocide name.

IMO, the exact word used doesn't matter so long as people know what you're talking about. But I'd definitely discount "No Mercy" has nearly as much traction as "Genocide" in the community. It seems like when someone says "No Mercy", there's usually a follow up question of "Oh, did you kill everything? Like, the genocide route? Or just killed everything you encountered and got the worst neutral ending where sans threatens you on the phone call at the end?"

That said, it's really only an effective criticism of the term "No Mercy", and not really an argument in favor of the Genocide route. I'm merely defaulting to the term because it appears to be the clearest well known term.

I couldn't care less if the route we called "Extinctionist" or "Bad Time" or whatever. As long as you can say the term and people will instantly know exactly what you mean without spoilers, in the event they don't know about it yet.

Can someone explain to me why is it offensive? Like the player literally eliminates and hunt monsters just because they are monsters in this route, the player kills everyone, the player makes monsters run for their lifes and abandon the cities that they lived, and all of this is not offensive but using the word genocide is? No one that played the game experienced the holocaust, no one, and the word is just offensive for some because of the holocaust and not because of the others genocides, if people were talking about the Rwandan genocide I would take this whining more serious, because it was recent, had so much more deaths than the holocaust and there is the posibility of people that suffered from it actually playing the game and that would be a legit reason to be offended about.

So it appears that there's more evidence supporting "Genocide Run/Route" than any other title. People have to keep in mind that, as stated numerous times already, Toby Fox himself has used the term on Twitter. I have tweeted to him today asking about what the true name of the ending was but he has yet to respond (and I doubt he will, to be frank.) In the meantime, I firmly believe it should be called "Genocide Run/Route."

I am in favor of being against the "Genocide Route" term

I would say calling the route "Murder route" would have a similar meaning, and is even shown to be specially quoted in the naming of the character with "That's a little on-the-nose, isn't it...?" after imputing "MURDER" as the players name. Putting "MERCY" as the players name has a similar effect as well. I have no thoughts against calling it the term "Genocide Route" other than that calling it "Murder Route" would be more canon, supported by the reasoning above.

I support the name "Genocide Route".

1.) Because "No Mercy" is the name of a different, Neutral route. For the actual Genocide Route, one has to kill all significant characters AND grind until there is no one left. (also, is it possible to spare a mook monster and stay on the Genocide route?)

2.) It's the most well-known.

3.) It's a very accurate descriptor. Sure, genocide is a nasty occurence, but so is murder, massacre, etc etc, aren't those all also pretty gruesome as well? It's not like it's being named after a specific genocide that has occured in the real world.

Some people (most notable those on TV Tropes) say that the name "Genocide route" spoils the nature of the route, but I don't really see it to be honest. By that logic, wouldn't "Pacifist route" also be considered a spoilery name?

can we call the worst route the "stab stab everyone's sad" route

Genocide route does have a lot of traction now, but I feel like calling it the Bad Time route might be best? A lot of people are switching from using Genocide route, and its pretty not good to keep using a word when people have a problem with it.