[1] : The Collaborative International Dictionary of English v.0.48

hard-bitten \hard-bitten\ hard-boiled \hard-boiled\adj.
   not given to sentimentality or gentleness; -- of people; as,
   a hard-bitten character.

   syn: pugnacious, tough.
        wordnet 1.5 +pjc

[2] : The Collaborative International Dictionary of English v.0.48

hard-boiled \hard-boiled\ adj.
   1. same as hard-bitten.

   syn: hard-bitten, pugnacious.
        wordnet 1.5

   2. emotionally hardened; -- used of persons.

   syn: callous, case-hardened, hardened.
        wordnet 1.5

   3. cooked until the yolk is solid; -- used of eggs; as, a
      breakfast of pancakes and hard-boiled eggs.
      wordnet 1.5
see also:
hard-bitten 

[3] : WordNet (r) 2.0

hard-boiled
     adj 1: tough and callous by virtue of experience syn: hard-bitten,
             pugnacious
     2: used of persons; emotionally hardened; "faced a
        case-hardened judge" syn: case-hardened, hardened
     3: used of eggs cooked until the yolk is solid
see also:
hard-bitten pugnacious case-hardened hardened 

Hard-Boiled >> H Words
Hard-Boiled, definition of term: Hard-Boiled
hard-boiled_pag1.html