To "jump one's case" means to confront or criticize someone aggressively. The antonyms, or words with opposite meanings, for this phrase would be words that suggest a peaceful or gentle approach. These could include terms like appreciate, compliment, or encourage. Instead of jumping someone's case, we could choose to praise their efforts, listen to their perspective, or offer constructive feedback in a respectful manner. By choosing to use positive language and actions, we can create more harmonious relationships and avoid unnecessary conflict.