"Bouches-du-Rhône" meaning in Breton

{
  "categories": [
    {
      "kind": "other",
      "name": "Noms propres en breton",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Breton",
      "orig": "breton",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Breton",
  "lang_code": "br",
  "pos": "name",
  "pos_title": "Nom propre",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Départements de France en breton",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Bouches-du-Rhône (département français)."
      ],
      "id": "fr-Bouches-du-Rhône-br-name-1ISRi8W3",
      "topics": [
        "geography"
      ]
    }
  ],
  "word": "Bouches-du-Rhône"
}

{
  "categories": [
    "Noms propres en breton",
    "breton"
  ],
  "lang": "Breton",
  "lang_code": "br",
  "pos": "name",
  "pos_title": "Nom propre",
  "senses": [
    {
      "categories": [
        "Départements de France en breton"
      ],
      "glosses": [
        "Bouches-du-Rhône (département français)."
      ],
      "topics": [
        "geography"
      ]
    }
  ],
  "word": "Bouches-du-Rhône"
}