hardbitten

adj.

1. 久经磨练而坚强的
   not easily shocked and not showing emotion, because you have experienced many unpleasant things

1. ADJ-GRADED （常指因经历过很多不幸而）冷酷无情的，铁石心肠的
   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.
   1. ...a cynical hard-bitten journalist.
      愤世嫉俗、冷酷无情的记者