Taking one on can be defined as confronting a difficult situation or challenge head-on. The antonyms for this phrase can be avoiding, shying away, or surrendering. Avoiding implies the act of evading an unpleasant situation rather than facing it. Shying away means hesitating or stepping back from a confrontation or responsibility. Surrendering refers to resigning oneself to defeat or giving up without putting up a fight. All these antonyms portray a lack of courage, determination, and resilience that are required to overcome life's challenges. Therefore, taking one on is a valuable trait that should be nurtured and encouraged in individuals.