Ferventness refers to the intensity and passion with which a person approaches a particular situation, idea, or emotion. Antonyms for ferventness include indifference, apathy, calmness, and detachment. These words suggest a lack of interest, enthusiasm, or emotion in a particular matter. While ferventness might be associated with strong feelings of love, joy, or excitement, apathy and indifference suggest a lack of emotion or concern. Calmness, on the other hand, conveys a sense of serenity and tranquility, while detachment suggests a degree of separation or disinterest. In sum, when one uses antonyms to ferventness, it suggests a lack of passion or enthusiasm in a particular context.