i have to say this is not a political post. i am not a us citizen and do not live there and do not really care who wins the election there.

my question is about whether there is a name for a process of evolution in meaning and usage. i have seen the phrase "MSM" used a lot in various comments at blogs all over the net and the first time i saw this initialism it took me a few minutes to parse it as "mainstream media". the phrase now does not mean "mainstream" in the OED sense of "the prevailing trend of opinion, fashion, society" or "belonging to or characteristic of an established tradition, field of activity, etc.; conventional" but is now pejorative meaning "media whose views are not the same as mine". ive seen it used by large organisations like FoxNews and the Washington Times in this sense, both excluding themselves from the definition. ive also seen it used liberally by individuals posting comments to blogs. supporters of both parties have used "MSM" to describe media that they think is biased against their candidate.

i guess the path "MSM" is taking is similar to that of "reactionary" but its interesting that unlike words like 'conservative' which are only used pejoratively by one side of a political argument, "MSM" is now firmly pejorative for both sides. Does this sort of meaning or usage shift have a name, and is there any sense of how long a particular usage has to be around before it becomes a recognized norm say in a dictionary?

Semantic Shift

Semantic Shift

It is also called semantic change. This article lists some of the different types of semantic change (link). It is a rather common occurrence in languages in general and has been studied by linguists for almost two centuries.

MSM seems to be used by both wings of the blogosphere in discussions of biases in the media. Other terms are liberal media and so-called liberal media used by the right and left respectively. In the days of yore, folks discussed the Fourth Estate (link).

Semantic shift and semantic change don't describe the specific kind of shift where a term has become pejorative to everybody using the term.

[It] don't describe the specific kind of shift where a term has become pejorative to everybody using the term.

If a majority of folks is using the phrase with a new meaning, rather than the older one, that seems like a classic case of semantic change to me.

thanks everyone. I guess its semantic shift because thats easier to say than semantic change.

latishya, sounds like you're becoming a semasiologist! :-)

That would be at the very least a subset of Semantic Shift/Change.

Whether there is a more specific term I don't know, but I can't think of one offhand. Pejorativisation?

I think I worded my response badly. I didn't mean to suggest that it was not an example of semantic change or semantic shift, merely that caling it semantic change or shift does not differentiate it from more benign examples of semantic change.