"mer du Nord" meaning in French

{
  "head_templates": [
    {
      "args": {
        "1": "f",
        "head": "mer du Nord"
      },
      "expansion": "mer du Nord f",
      "name": "fr-proper noun"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "name",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "French 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"
        },
        {
          "kind": "place",
          "langcode": "fr",
          "name": "Belgium",
          "orig": "fr:Belgium",
          "parents": [
            "Europe",
            "Earth",
            "Eurasia",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "place",
          "langcode": "fr",
          "name": "Denmark",
          "orig": "fr:Denmark",
          "parents": [
            "Europe",
            "Earth",
            "Eurasia",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "place",
          "langcode": "fr",
          "name": "France",
          "orig": "fr:France",
          "parents": [
            "Europe",
            "Earth",
            "Eurasia",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "place",
          "langcode": "fr",
          "name": "Germany",
          "orig": "fr:Germany",
          "parents": [
            "Europe",
            "Earth",
            "Eurasia",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "place",
          "langcode": "fr",
          "name": "Netherlands",
          "orig": "fr:Netherlands",
          "parents": [
            "Europe",
            "Earth",
            "Eurasia",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "place",
          "langcode": "fr",
          "name": "Norway",
          "orig": "fr:Norway",
          "parents": [
            "Europe",
            "Earth",
            "Eurasia",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "place",
          "langcode": "fr",
          "name": "Seas",
          "orig": "fr:Seas",
          "parents": [
            "Bodies of water",
            "Places",
            "Landforms",
            "Water",
            "Names",
            "Earth",
            "Liquids",
            "All topics",
            "Proper nouns",
            "Terms by semantic function",
            "Nature",
            "Matter",
            "Fundamental",
            "Nouns",
            "Chemistry",
            "Lemmas",
            "Sciences"
          ],
          "source": "w"
        },
        {
          "kind": "place",
          "langcode": "fr",
          "name": "United Kingdom",
          "orig": "fr:United Kingdom",
          "parents": [
            "British Isles",
            "Europe",
            "Islands",
            "Earth",
            "Eurasia",
            "Places",
            "Nature",
            "Names",
            "All topics",
            "Proper nouns",
            "Terms by semantic function",
            "Fundamental",
            "Nouns",
            "Lemmas"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "North Sea"
      ],
      "id": "en-mer_du_Nord-fr-name-2fH3MlKV",
      "links": [
        [
          "North Sea",
          "North Sea"
        ]
      ],
      "tags": [
        "feminine"
      ],
      "wikipedia": [
        "fr:mer du Nord"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/mɛʁ dy nɔʁ/"
    }
  ],
  "word": "mer du Nord"
}

{
  "head_templates": [
    {
      "args": {
        "1": "f",
        "head": "mer du Nord"
      },
      "expansion": "mer du Nord f",
      "name": "fr-proper noun"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "name",
  "senses": [
    {
      "categories": [
        "French entries with incorrect language header",
        "French feminine nouns",
        "French lemmas",
        "French multiword terms",
        "French proper nouns",
        "French terms with IPA pronunciation",
        "Pages with 1 entry",
        "Pages with entries",
        "fr:Belgium",
        "fr:Denmark",
        "fr:France",
        "fr:Germany",
        "fr:Netherlands",
        "fr:Norway",
        "fr:Seas",
        "fr:United Kingdom"
      ],
      "glosses": [
        "North Sea"
      ],
      "links": [
        [
          "North Sea",
          "North Sea"
        ]
      ],
      "tags": [
        "feminine"
      ],
      "wikipedia": [
        "fr:mer du Nord"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/mɛʁ dy nɔʁ/"
    }
  ],
  "word": "mer du Nord"
}