"радијум" meaning in Serbian

{
  "forms": [
    {
      "form": "радијум"
    }
  ],
  "lang": "Serbian",
  "lang_code": "sr",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Χημεία (σερβικά)",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "το ράδιο"
      ],
      "id": "el-радијум-sr-noun-qU9x3XwE",
      "raw_tags": [
        "χημεία"
      ]
    }
  ],
  "word": "радијум"
}

{
  "forms": [
    {
      "form": "радијум"
    }
  ],
  "lang": "Serbian",
  "lang_code": "sr",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Χημεία (σερβικά)"
      ],
      "glosses": [
        "το ράδιο"
      ],
      "raw_tags": [
        "χημεία"
      ]
    }
  ],
  "word": "радијум"
}