[beeforpork]

'dark matter' is not a theory, it is the name of an observational problem.

There are many theories to explain dark matter observations. MOND is not a competitor with 'dark matter', because MOND is a theory and it tries to explain some aspects (spiral galaxy rotation) of what is observed as the dark matter problem, which consists of many more observations. There is no competition here. There are other theories to explain dark matter, like dark matter particle theories involving neutrinos or whatever, and these may be called competitors, but dark matter itself is not a theory, but a problem statement.

[XorNot]

Yes and no...MOND's core proposition is that dark matter doesn't exist, and instead modified gravity does.

Whereas you can have many proposals for what dark matter is, provided it is capable of being almost entirely only gravitationally interacting, and there's enough of it.

MOND has had the problem that depending which MOND you're talking about, it still doesn't explain all the dark matter (so now you're pulling free parameters on top of free parameters).

[wavemode]

I've seen this opinion before, but can't seem to square it with any reliable source.

Wikipedia has: "dark matter is a hypothetical form of matter that appears not to interact with light or the electromagnetic field ... Although the astrophysics community generally accepts dark matter's existence, a minority of astrophysicists, intrigued by specific observations that are not well-explained by ordinary dark matter, argue for various modifications of the standard laws of general relativity. These include modified Newtonian dynamics, tensor–vector–scalar gravity, or entropic gravity."

Even its name, "dark matter", sort of strongly implies this. If someone were just trying to refer to the observations, rather than a specific explanation for the observations, wouldn't they just say "abnormal galaxy rotation curves" rather than "dark matter"?

I'm not saying Wikipedia is an end-all-be-all source on this, I'm just asking where you're getting this alternate definition. If it is somewhere reliable then perhaps the article needs to be rephrased.

[andrewflnr]

As far as I know it's from here: https://www.youtube.com/watch?v=PbmJkMhmrVI As I said elsewhere in this thread, I think she's trying to make some meta point but ends up just muddying the water.