Effeteness is defined as a lack of energy, strength or vigor. Some antonyms for this word can be robustness, vitality, stamina, power and vigor. These words convey strength, energy and endurance which are the opposite of effeteness. Other antonyms include resilience, brawn and hardiness that are closely related to physical fitness and toughness. Whereas, mental sharpness and alertness can be expressed by antonyms such as agility, quickness, keenness, alertness and shrewdness. These antonyms promote the idea of being strong, active and fit both physically and mentally. Contrastingly, effeteness implies a dull or weak presence.