Audiophile slang
Veiled
Also called veil, the Sennheiser veil
Veiled describes a sound that seems to come through a thin curtain: the detail is there but softened, as if the upper midrange and treble were turned down a notch. It is the standard complaint about relaxed or dark tunings.
The classic case is the "Sennheiser veil", a term attached to the HD 600 and HD 650 and their slightly recessed upper Mids and gentle Treble. Fans hear a smooth, long-session tuning; critics hear a veil. The Frequency response is the same either way, which makes it a good example of a description that is really a preference.
A veiled impression can also come from a poor seal, a worn pad or an underpowered Amplifier, so it is worth ruling those out before blaming the tuning. The opposite impression is Bright or Analytical.