"lingua materna" meaning in Galician

{
  "forms": [
    {
      "form": "linguas maternas",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "f"
      },
      "expansion": "lingua materna f (plural linguas maternas)",
      "name": "gl-noun"
    }
  ],
  "lang": "Galician",
  "lang_code": "gl",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Galician entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "gl",
          "name": "Language",
          "orig": "gl:Language",
          "parents": [
            "Communication",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "mother tongue"
      ],
      "id": "en-lingua_materna-gl-noun-eUb2gChl",
      "links": [
        [
          "mother tongue",
          "mother tongue"
        ]
      ],
      "tags": [
        "feminine"
      ]
    }
  ],
  "word": "lingua materna"
}

{
  "forms": [
    {
      "form": "linguas maternas",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "f"
      },
      "expansion": "lingua materna f (plural linguas maternas)",
      "name": "gl-noun"
    }
  ],
  "lang": "Galician",
  "lang_code": "gl",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Galician countable nouns",
        "Galician entries with incorrect language header",
        "Galician feminine nouns",
        "Galician lemmas",
        "Galician multiword terms",
        "Galician nouns",
        "gl:Language"
      ],
      "glosses": [
        "mother tongue"
      ],
      "links": [
        [
          "mother tongue",
          "mother tongue"
        ]
      ],
      "tags": [
        "feminine"
      ]
    }
  ],
  "word": "lingua materna"
}