I think there are many random terms being used for guitar tone that sometimes make things a bit too difficult. Here's how I view some of these terms:
Open = wide; full range; flat; equal amount of bass, middle and treble and even presence so that no frequency area is overbearing = this leads to a sound where every note can be heard clearly and gives you perfect note separation.
Fat = compressed low-mid range that's in control of the guitar sound
Warm = super pleasant high end frequency roll off in the high end
Dry = very little gain (kind of like the mix control on effects: dry = less)
Wet = a lot of gain (kind of like the mix control on effects: wet = more)
And my ultimate favorite:
Amp in the room = .... well an amp on it's own actually makes no sound...
I've steered people in completely wrong directions because of terms like these and people having different views on what they mean.
F.ex. some people consider "dry = too much high end like a sore throat" and some people consider "dry = not enough high end as in not wet enough". If only there was a thesaurus for guitar terms to make our lives easier.