stubborn

a mark or spot that is very difficult to remove

a part of a person's character that makes them stubbornly determined

an unwavering negative response to a request or demand

strong and persistent opposition

an unyielding resolve to do something

the act of firmly stating that something is true or demanding that something be done

the quality of continuing to do something despite difficulty or opposition

a type of pride that prevents one from changing their mind or admitting fault

often used in the simile 'as stubborn as a mule'

refers to a facial expression, particularly the set of the jaw, suggesting determination