[化] 平直度; 平整度; 平面度

[医] 实音

1. the property of having two dimensions

<noun.attribute>

2. a want of animation or brilliance

<noun.communication>
the almost self-conscious flatness of Hemingway's style

3. a deficiency in flavor

<noun.cognition>
it needed lemon juice to sharpen the flatness of the dried lentils

4. the property of having little or no contrast; lacking highlights or gloss

<noun.attribute>

5. inactivity; showing an unusual lack of energy

<noun.attribute>
the general appearance of sluggishness alarmed his friends