(1):

(n.) Depression of tone; the state of being below the true pitch; - opposed to sharpness or acuteness.

(2):

(n.) The quality or state of being flat.

(3):

(n.) Eveness of surface; want of relief or prominence; the state of being plane or level.

(4):

(n.) Want of vivacity or spirit; prostration; dejection; depression.

(5):

(n.) Want of variety or flavor; dullness; insipidity.