"moyen breton" meaning in French

{
  "head_templates": [
    {
      "args": {
        "1": "m",
        "2": "-"
      },
      "expansion": "moyen breton m (uncountable)",
      "name": "fr-noun"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "noun",
  "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": "topical",
          "langcode": "fr",
          "name": "Languages",
          "orig": "fr:Languages",
          "parents": [
            "Language",
            "Names",
            "Communication",
            "All topics",
            "Proper nouns",
            "Terms by semantic function",
            "Fundamental",
            "Nouns",
            "Lemmas"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Middle Breton (language)"
      ],
      "id": "en-moyen_breton-fr-noun-jI3JH-4Z",
      "links": [
        [
          "Middle Breton",
          "Middle Breton"
        ]
      ],
      "related": [
        {
          "word": "vieux breton"
        }
      ],
      "tags": [
        "masculine",
        "uncountable"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/mwa.jɛ̃ bʁə.tɔ̃/"
    }
  ],
  "word": "moyen breton"
}

{
  "head_templates": [
    {
      "args": {
        "1": "m",
        "2": "-"
      },
      "expansion": "moyen breton m (uncountable)",
      "name": "fr-noun"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "noun",
  "related": [
    {
      "word": "vieux breton"
    }
  ],
  "senses": [
    {
      "categories": [
        "French entries with incorrect language header",
        "French lemmas",
        "French masculine nouns",
        "French multiword terms",
        "French nouns",
        "French terms with IPA pronunciation",
        "French uncountable nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "fr:Languages"
      ],
      "glosses": [
        "Middle Breton (language)"
      ],
      "links": [
        [
          "Middle Breton",
          "Middle Breton"
        ]
      ],
      "tags": [
        "masculine",
        "uncountable"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/mwa.jɛ̃ bʁə.tɔ̃/"
    }
  ],
  "word": "moyen breton"
}