What is Warmth?

Would someone kindly explain the audiophile term "warmth?" Most appreciated.
Dear Suteetat: ++++++ " it is difficult to define such a subjective term. " +++++

yes, this is the main issue on that word. Now, I think that people is using the warm term/word to define an instrument/audio system or the like about its intrinsecal " tone ".
Now, you are an experienced/pro piano player: which other word came to you other than warmth when you compare the Grotrian grand piano against a Steinway or other one? which other word could give you/us a better definition of each piano overall tone color?

I have some difficult about because here in México we don't use the warmth meaning to compare different tone colors in music instrumentation or audio systems.

That's why maybe what Wolf posted: +++ Warmth for me is lack of harshness " +++ makes no precise means to me.

Regards and enjoy the music,
This is worse than I thought!! All I asked for was an "audiophile" definition of warmth. I'm not reading a uniformed, consistent AND objective definition among the group. I'd hate to ask the group to define imaging or timbre!!
Well, if we use subjective descriptions (and I think we must), we have to expect subjectivity in their definitions! You might find it helpful to consider warmth in the light of its opposites - all rather harsh terms like dry, detailed, clinical. I tend to think of a continuum with warmth at one end, detailed at the other, and accuracy somewhere in between.
That's because some people want to hang on to their personal misconceptions rather than accept the fact that the original meaning has already been defined, and adjust accordingly.