"σιδηροδρομικώς" meaning in Greek

{
  "forms": [
    {
      "form": "sidirodromikós",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "adverbs",
        "3": "",
        "4": "",
        "5": "",
        "6": "",
        "head": "",
        "sort": ""
      },
      "expansion": "σιδηροδρομικώς • (sidirodromikós)",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "σιδηροδρομικώς • (sidirodromikós)",
      "name": "el-adv"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Greek 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"
        }
      ],
      "glosses": [
        "by rail"
      ],
      "id": "en-σιδηροδρομικώς-el-adv-1ET13YO5",
      "links": [
        [
          "rail",
          "rail"
        ]
      ],
      "related": [
        {
          "english": "railway",
          "roman": "sidirodromikós",
          "tags": [
            "adjective"
          ],
          "word": "σιδηροδρομικός"
        }
      ]
    }
  ],
  "word": "σιδηροδρομικώς"
}

{
  "forms": [
    {
      "form": "sidirodromikós",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "adverbs",
        "3": "",
        "4": "",
        "5": "",
        "6": "",
        "head": "",
        "sort": ""
      },
      "expansion": "σιδηροδρομικώς • (sidirodromikós)",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "σιδηροδρομικώς • (sidirodromikós)",
      "name": "el-adv"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "adv",
  "related": [
    {
      "english": "railway",
      "roman": "sidirodromikós",
      "tags": [
        "adjective"
      ],
      "word": "σιδηροδρομικός"
    }
  ],
  "senses": [
    {
      "categories": [
        "Greek adverbs",
        "Greek entries with incorrect language header",
        "Greek lemmas",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "by rail"
      ],
      "links": [
        [
          "rail",
          "rail"
        ]
      ]
    }
  ],
  "word": "σιδηροδρομικώς"
}