D defs.my
Entry 5 senses Webster, 1913

flatness

· flat·ness · IPA /ˈflætnəs/
01 n. The quality or state of being flat.
  1. 1.
    The quality or state of being flat.
  2. 2.
    Eveness of surface; want of relief or prominence; the state of being plane or level.
  3. 3.
    Want of vivacity or spirit; prostration; dejection; depression.
  4. 4.
    Want of variety or flavor; dullness; insipidity.
  5. 5.
    Depression of tone; the state of being below the true pitch; -- opposed to sharpness or acuteness.