The antonyms for the word "toughens up" include words such as weaken, soften, coddle, pamper, mollycoddle, indulge, and baby. These words describe actions that significantly counteract the process of toughening up. Toughening up implies becoming strong, resilient, and unyielding. Yet, the antonyms suggest activities that undermine physical and mental toughness. An individual who indulges in habits that weaken their resolve or overly insulate themselves from hardship is unlikely to develop resilience or hardiness. Instead, they risk becoming fragile and vulnerable to stress and adversity. Therefore, it is essential to avoid actions that oppose the process of toughening up and strive to build resilience and strength.