The phrase "clams up" refers to someone becoming silent or refusing to speak. Its antonyms include words like "open up," "speak out," "communicate," "express," and "reveal." When a person opens up, they share their thoughts and feelings freely without reservation. Speaking out means expressing your opinions and standing up for what you believe in. Communication involves both verbal and nonverbal cues and actively listening to the other person. Meanwhile, expressing yourself means giving voice to your emotions and ideas. Finally, revealing yourself means disclosing personal information to others. These antonyms to "clams up" encourage individuals to connect with others and foster healthy relationships with those around them.