The phrase "turn thumbs down" typically means to reject or disapprove of something. Some antonyms for this phrase might include "approve," "accept," "support," or "endorse." When someone turns their thumbs up, it usually indicates agreement or approval, while turning them down suggests the opposite. Some synonyms for "turn thumbs down" might include "veto," "deny," "refuse," or "reject." It's important to consider context when using these phrases, as they may have different meanings depending on the situation. Ultimately, having a diverse vocabulary of words and phrases can help us communicate more effectively and express ourselves with greater precision.