Here's why:
* Validate: To confirm or establish the truth or accuracy of something.
* Denounce: To publicly criticize or condemn something.
Antonyms for "denounce" would include:
* Praise
* Commend
* Approve
* Support
While "validate" and "denounce" are opposite in their meaning, they aren't direct opposites. They deal with different concepts. "Validate" focuses on proving truth, while "denounce" focuses on expressing disapproval.