gritty hard-bitten坚韧不拔的
hard-bitten indomitable unbent unbowed不屈服的
to be hard-bitten would要顽强会
ADJ（形容词） If you describe someone as hard-bitten, you are critical of them because they do not show much emotion or have much sympathy for other people, usually because they have experienced many unpleasant things. (常指因经历过很多艰苦而)铁石心肠的; 麻木不仁的 [usu ADJ n] [表不满]
...a cynical hard-bitten journalist.
...一位愤世嫉俗、麻木不仁的记者。