Noun

• S: (n) two-dimensionality, flatness, planeness (the property of having two dimensions)
• S: (n) flatness (a want of animation or brilliance) "the almost self-conscious flatness of Hemingway's style"
• S: (n) flatness (a deficiency in flavor) "it needed lemon juice to sharpen the flatness of the dried lentils"
• S: (n) flatness, lusterlessness, lustrelessness, mat, matt, matte (the property of having little or no contrast; lacking highlights or gloss)
• S: (n) languor, lethargy, sluggishness, phlegm, flatness (inactivity; showing an unusual lack of energy) "the general appearance of sluggishness alarmed his friends"