The word "Grunge" was actually used by one of the first "so called" grunge band's vocalist from Green River I think) to define the grungy sound of its band.
Grunge is actually a real word that matches perfectly with the sound of these bands.
Then it became a movement and a lot of band started to use this sound, and it was, of course, called "Grunge".
But well, everybody knows how the society is and how it tries to recuperate everything...so everything became "Grunge" at the time, from the time it came from Seattle or the guys wore the "Grunge style", but Pearl Jam, Soundgarden or Alice in Chains, for exemple, even if they had a dirty sound and were dressed Grunge had nothing to do with this movement in my opinion.
You're right, it's all about 90's alternative rock bands, and I love this era so much, I just don't give a fuck about how they try to name this. It becomes too complicated how music is tagged today, there are ten thousand different genres of metal and new stupid genres everyday, it's music after all and there are just 10 genres, the rest is drift or invention.

I love Grunge!!! It has that heavy and mellow mix that is just awesome!!!

Grunge is a commercial term? Yes it is!!

Of course its a commercial term! Press together with music industry has always had the desire to come up with a new ''brand'' or a name, to disguise some old shit in a new, nicely wrapped package and empty the pockets of frustrated teenagers.

Don't get me wrong, I love grunge, I wouldn't be in this group otherwise, but that's sadly the case in most genres these days

Ariues said:
music over titles. arguing about words is so non-punk. people that like this music should just call it what we wanna and not worry about what the media or corporate people wanna say. beit grunge, 90s alternative, or watever. call it what you wanna. its great rock music- i think thats most important. corporate labels and the like are souless anyway.

Exactly