The phrase "packed it in" typically refers to quitting, giving up, or ceasing a particular activity or pursuit. Its antonyms include perseverance, determination, persistence, tenacity, and resilience. To persevere is to continue despite difficulties or obstacles, while determination is characterized by a firmness of purpose, resolve, and unwavering commitment. Persistence involves steadfastness and the ability to maintain effort even in the face of adversity, while tenacity is defined as resolute persistence or stubbornness in achieving a goal. Resilience implies the ability to bounce back from setbacks or challenges, often with renewed motivation to succeed. All of these traits oppose the notion of "packing it in" or giving up on a goal or endeavor.