Invalidating means rendering something or someone invalid or of no worth. Antonyms for invalidating include validating, upholding, supporting, approving, confirming, affirming, endorsing, and agreeing with. When validating something, you are making it officially acceptable and legitimate, and acknowledging its worth or existence. When you approve or endorse something, you're giving it your blessing, and acknowledging its value. Confirming something means verifying its accuracy, and agreeing with it means considering it acceptable or plausible. All these antonyms highlight the opposite of invalidating, which is to validate, support, or acknowledge the value or worth of something or someone.