The word "most giving-in" implies someone who tends to give up easily or surrender easily in any situation. Antonyms, on the other hand, would mean the opposite of this trait, someone who is determined, firm and refuses to give up easily. Some of the antonyms for "most giving-in" can be strong-willed, uncompromising, unyielding, tough, and resolute. These words signify someone who is not easily influenced or swayed, someone who stands up for their beliefs and won't give up on their goals. Being strong-willed and determined is necessary in life to achieve success and overcome challenges.