Effetenesses means a lack of vigor or energy, and therefore antonyms for this word would include strength, vitality, power, and potency. These words are all associated with energy and robustness. Another set of antonyms for effetenesses could include determination, assertiveness, and confidence. These words describe the ability to take charge and make decisions, which are traits often associated with energetic, dynamic individuals. Additionally, antonyms for effetenesses might include bravery, courage, or fearlessness, as these words suggest a willingness to take on challenges and overcome obstacles, indicating a strong sense of purpose and motivation.