"Holding out on" usually means keeping information or resources intentionally and not sharing them with others. The opposite of holding out on would be to share, give, reveal, or disclose. These antonyms suggest the opposite of hoarding, hiding or keeping something secret. If you are not holding out on someone, you are open, transparent, and generous. Other antonyms may include collaborating, cooperating, sharing openly, teamwork, and supportiveness. People who are not holding out on, tend to be honest, trustworthy, friendly, and respectful of others' needs. Therefore, the antonyms of holding out on necessitate positive behaviors that build relationship and create trust.