Antonyms for "speak in favor" include "speak against," "oppose," "disapprove," "criticize," and "condemn." These words signify a negative or opposing sentiment towards the subject, person, or idea being discussed. It is important to have a balanced discussion by considering different opinions and views. However, when we speak in favor, we express our support and agreement with the topic or person. Conversely, when we speak against, we express our disagreement or opposition to the subject. Using antonyms for "speak in favor" can help create a more nuanced, multifaceted perspective on a subject or issue by balancing the positive with negative viewpoints.