Antonyms for "gave pep talk" include dishearten, discourage, demoralize, abash, depress and deject. Instead of a pep talk, one might offer criticism, skepticism, or even disdain. A pep talk encourages, motivates and inspires, while its antonyms have the opposite effect, demotivating, disheartening and discouraging. Providing negative feedback or criticism, belittling someone's efforts, or highlighting their failures rather than their accomplishments can all be forms of antonyms to a pep talk. When trying to inspire others, it is essential to stay positive, cheerful and encouraging while avoiding antonyms that may undermine your efforts.