There are several synonyms for the word "hardcase," which is commonly used to describe a tough or stubborn person. One alternative is "tough nut," which emphasizes the challenging nature of dealing with such a person. Another option is "hard-nosed," which highlights the uncompromising and unyielding personality traits of the individual. "Stalwart" is another synonym that can be used to describe someone who is steadfast and unwavering in their beliefs or actions. Alternatively, "iron-willed" conveys a similar sense of determination and resilience. Other options include "bullheaded," "obstinate," and "tenacious." Regardless of the synonym used, these terms all describe individuals who are known for their toughness and resilience.