"Have the quivers" is an idiomatic expression that denotes feeling shaky, nervous, or scared. Antonyms for this phrase include feeling brave, calm, collected, confident, fearless, and poised. When someone is brave, he or she is not easily intimidated and has the courage to face new challenges with determination. Calmness, on the other hand, is a state of tranquility and serenity that allows individuals to maintain their composure and deal with difficult situations effectively. Similarly, feeling collected and poised indicates a level of self-confidence and self-assurance that helps people to stay focused and composed in the toughest of times. In short, antonyms for "have the quivers" revolve around feelings of strength, courage, and composure.