It's minimalist if you consider "minimalism" to mean minimal decoration. Instead of, you know, minimalism.

I kept telling Steve we needed more padding between those links ;) check out how it used to look... http://reddit.blogspot.com/2006/12/time-machine.html

Is there some generally agreed upon definition for that?

Yes.

Semi-agreed. Reddit is minimal in that it is pretty simple and straightforward to use. Not minimal in the designed-to-be minimalist sense.

The best example of this is Google and Apple. Both are minimalist. But Apple (arguably, of course) has a much better sense of design. Reddit is like Google.

I'm not in the Apple boat, but I do know what you mean about the Google-iness of Reddit, and more generally the Google-iness of Google. Aside from google.com itself, there's something about everything they design that is very off-putting in a way that's hard to describe.

Lack of whitespace? Google Mail, YouTube, even their help pages are crammed full of content.

To my eye anyway it always looks like Google got the developers to do the design as well (even though that's probably not the case), whereas Apples' designs have a little bit more of an "artistic" feel to them

turn on compressed link display in your preferences. it's what reddit originally looked like, and it's much more minimal than the current design