Which word is most opposite in meaning to "veracity"?

The word "veracity" refers to truthfulness or accuracy in reporting or being honest. Therefore, to find the antonym of "veracity," one should look for a word that suggests a lack of truthfulness.

Duplicity fits this requirement perfectly, as it denotes deceitfulness or double dealing—essentially, it involves being untruthful or misleading. When someone demonstrates duplicity, they are acting in direct opposition to the principles of veracity by not being honest or straightforward.

In contrast, the other words do not convey the same relationship to truthfulness. Uncleanliness relates to hygiene and does not impact truthfulness. Opaqueness involves being unclear or difficult to understand, and while it might suggest some lack of clarity, it doesn’t directly reference honesty or dishonesty. Credibility refers to the quality of being believable or trustworthy, which is aligned with truthfulness rather than opposite to it. Thus, duplicity is the most fitting opposite of veracity.