"ferro-" meaning in Polish

{
  "etymology_templates": [
    {
      "args": {
        "1": "pl",
        "2": "der",
        "3": "la>ferrum>iron",
        "id": "iron",
        "tree": "1"
      },
      "expansion": "Etymology tree\nLatin ferrumder.\nPolish ferro-",
      "name": "etymon"
    },
    {
      "args": {
        "1": "derived terms",
        "2": "Derived"
      },
      "expansion": "Derived",
      "name": "glossary"
    },
    {
      "args": {
        "1": "pl",
        "2": "la",
        "3": "ferrum",
        "4": "",
        "5": "",
        "g": "",
        "g2": "",
        "g3": "",
        "id": "",
        "lit": "",
        "nocat": "",
        "pos": "",
        "sc": "",
        "sort": "",
        "tr": "",
        "ts": ""
      },
      "expansion": "Latin ferrum",
      "name": "der"
    },
    {
      "args": {
        "1": "pl",
        "2": "la",
        "3": "ferrum"
      },
      "expansion": "Derived from Latin ferrum",
      "name": "der+"
    }
  ],
  "etymology_text": "Etymology tree\nLatin ferrumder.\nPolish ferro-\nDerived from Latin ferrum.",
  "head_templates": [
    {
      "args": {
        "1": "pl",
        "2": "prefix"
      },
      "expansion": "ferro-",
      "name": "head"
    }
  ],
  "hyphenation": [
    "[please"
  ],
  "lang": "Polish",
  "lang_code": "pl",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages using catfix",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 6 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Polish entries with Template:pl-pr without syllabification",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Polish entries with etymology trees",
          "parents": [
            "Entries with etymology trees",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Polish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "ferro- + magnetyzm → ferromagnetyzm",
          "type": "example"
        }
      ],
      "glosses": [
        "ferro-"
      ],
      "id": "en-ferro--pl-prefix-NX-2HZGR",
      "links": [
        [
          "ferro-",
          "ferro-#English"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/fɛr.rɔ/"
    },
    {
      "rhymes": "-ɛrrɔ"
    }
  ],
  "word": "ferro-"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "pl",
        "2": "der",
        "3": "la>ferrum>iron",
        "id": "iron",
        "tree": "1"
      },
      "expansion": "Etymology tree\nLatin ferrumder.\nPolish ferro-",
      "name": "etymon"
    },
    {
      "args": {
        "1": "derived terms",
        "2": "Derived"
      },
      "expansion": "Derived",
      "name": "glossary"
    },
    {
      "args": {
        "1": "pl",
        "2": "la",
        "3": "ferrum",
        "4": "",
        "5": "",
        "g": "",
        "g2": "",
        "g3": "",
        "id": "",
        "lit": "",
        "nocat": "",
        "pos": "",
        "sc": "",
        "sort": "",
        "tr": "",
        "ts": ""
      },
      "expansion": "Latin ferrum",
      "name": "der"
    },
    {
      "args": {
        "1": "pl",
        "2": "la",
        "3": "ferrum"
      },
      "expansion": "Derived from Latin ferrum",
      "name": "der+"
    }
  ],
  "etymology_text": "Etymology tree\nLatin ferrumder.\nPolish ferro-\nDerived from Latin ferrum.",
  "head_templates": [
    {
      "args": {
        "1": "pl",
        "2": "prefix"
      },
      "expansion": "ferro-",
      "name": "head"
    }
  ],
  "hyphenation": [
    "[please"
  ],
  "lang": "Polish",
  "lang_code": "pl",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        "Pages using catfix",
        "Pages with 6 entries",
        "Pages with entries",
        "Polish 2-syllable words",
        "Polish entries with Template:pl-pr without syllabification",
        "Polish entries with etymology trees",
        "Polish entries with incorrect language header",
        "Polish lemmas",
        "Polish prefixes",
        "Polish terms derived from Latin",
        "Polish terms with IPA pronunciation",
        "Polish terms with audio pronunciation",
        "Rhymes:Polish/ɛrrɔ",
        "Rhymes:Polish/ɛrrɔ/2 syllables"
      ],
      "examples": [
        {
          "text": "ferro- + magnetyzm → ferromagnetyzm",
          "type": "example"
        }
      ],
      "glosses": [
        "ferro-"
      ],
      "links": [
        [
          "ferro-",
          "ferro-#English"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/fɛr.rɔ/"
    },
    {
      "rhymes": "-ɛrrɔ"
    }
  ],
  "word": "ferro-"
}