"hard nail" meaning in English

{
  "forms": [
    {
      "form": "hard nails",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "hard nail (plural hard nails)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1912, Arthur Conan Doyle, The Lost World […], London; New York, N.Y.: Hodder and Stoughton, →OCLC:",
          "text": "\"He's a hard nail, is Jack, and a dead shot, too, but you can't leave a Grand National winner to die like that - what?\"",
          "type": "quote"
        }
      ],
      "glosses": [
        "A strong person, in character and physique."
      ],
      "id": "en-hard_nail-en-noun-E7mQR01j",
      "raw_glosses": [
        "(figurative) A strong person, in character and physique."
      ],
      "related": [
        {
          "word": "hard as nails"
        }
      ],
      "tags": [
        "figuratively"
      ]
    }
  ],
  "word": "hard nail"
}

{
  "forms": [
    {
      "form": "hard nails",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "hard nail (plural hard nails)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "hard as nails"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "ref": "1912, Arthur Conan Doyle, The Lost World […], London; New York, N.Y.: Hodder and Stoughton, →OCLC:",
          "text": "\"He's a hard nail, is Jack, and a dead shot, too, but you can't leave a Grand National winner to die like that - what?\"",
          "type": "quote"
        }
      ],
      "glosses": [
        "A strong person, in character and physique."
      ],
      "raw_glosses": [
        "(figurative) A strong person, in character and physique."
      ],
      "tags": [
        "figuratively"
      ]
    }
  ],
  "word": "hard nail"
}