"spring steel" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "spring steel (uncountable)",
      "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"
        }
      ],
      "glosses": [
        "A variety of steel, elastic, strong, and tough, rolled for making springs, etc."
      ],
      "id": "en-spring_steel-en-noun-kEzlMoJw",
      "tags": [
        "uncountable"
      ]
    }
  ],
  "word": "spring steel"
}

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "spring steel (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English uncountable nouns"
      ],
      "glosses": [
        "A variety of steel, elastic, strong, and tough, rolled for making springs, etc."
      ],
      "tags": [
        "uncountable"
      ]
    }
  ],
  "word": "spring steel"
}