名词

1. inactivity
showing an unusual lack of energy

e.g. the general appearance of sluggishness alarmed his friends

Synonym: languorlethargysluggishnessphlegm

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

Synonym: lusterlessnesslustrelessnessmatmattmatte

3. the property of having two dimensions

Synonym: two-dimensionalityplaneness

4. a deficiency in flavor

e.g. it needed lemon juice to sharpen the flatness of the dried lentils

5. a want of animation or brilliance

e.g. the almost self-conscious flatness of Hemingway's style