contradictory communication

Since what you hear is a combination of factors I would suggest that you cannot totally separate anything.....warm and transparency are different as Onhwy61 correctly points out but my guess is they are also related in the way the overall sound is perceived.

The relative balance between 1K and 8K frequency response can produce warmth.....basically a peak at 4K will sound more sound harsh (brighter brass) and a dip at around 4 K will sound warmer (less harsh).

However, there is another dimension to warm sound; more harmonics from some equipment like tube amps create more warmth to the sound by increasing the harmonic content....vinyl does much the same when compared to digital. Since harmonics are entirely natural to sound and crucial to the way you percieve them and the timbre...these added harmonics are often pleasing.

I guess I am suggesting that it is very hard to separate terms in audio as everything is interelated.

As should be obvious from this thread, none of these words mean anything.

Pabelson, Of course these words mean 'something', its just that one has to work hard to ferret out the meaning being applied by each user. No difference between how people apply modifiers to audio or anything else.

Some folks overvalue consistency I think - reminds me of an old saying about consistency being the bug-a-boo of the ...........(self-sensored so as not to offend). :-)

The thing is, anything can add or subtract from the musical content of a recording making it sound warm or lean(components, cables, speakers and even some power conditioning.) My idea is for instruments to sound like instruments provided the recording is not so hosed up as to relegate all this to a moot point.
I think warm is a valid term. It just doesn't register the same way with everybody.
As was mentioned above and I totally agree with, harmonic richness can be considered warm if it is over done.
We all sit around and respond to these posts and the more you read the less anything matters in the overall concept. Everyone likes what they like.
You could have the perfect system by every imaginable specification possible and it could stink.
Your room has SO much to do with the ultimate sound. Warmth, leaness, transparency, holographic imaging, etc, etc really mean little until you reference them to some standard. Therein lies the problem, they're no standards.
I have actually heard a few people say Vandersteen speakers sounded lean in their system. Hmmm! Everything is a SYSTEM. It has to be taken as a whole. It to me would be hard to review anything without having some sort of reference system [you] believe in. You can take an amp and throw it into 5 different system and get 5 different opinions because of the way it interfaces with a particular system.
I think it's time to lay semantics to rest and listen to some more music!

Of course these words mean 'something', its just that one has to work hard to ferret out the meaning being applied by each user. No difference between how people apply modifiers to audio or anything else.

There's a big difference. If I put my hand on top of an amp and say, "this amp is warm," you know something--you know its temperature exceeds room temperature, but is not so hot as to be untouchable. But if I describe the sound of that amp as "warm," you really can't be sure at all what I mean. In that case, "warm" isn't anchored to any scale that you can use to narrow down my meaning.

An interesting experiment would be to ask listeners to compare two components (blind, so they aren't influenced by prior information) and decide which one sounds warmer. Then see whether most people agree. Until somebody does that (and no one has, to my knowledge), there's no real evidence that "warm" means anything like the same thing to people.