"Lun" meaning in Breton

{
  "categories": [
    {
      "kind": "other",
      "name": "Noms propres en breton",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Breton",
      "orig": "breton",
      "parents": [],
      "source": "w"
    }
  ],
  "derived": [
    {
      "word": "Lun-Fask"
    }
  ],
  "lang": "Breton",
  "lang_code": "br",
  "pos": "name",
  "pos_title": "Nom propre",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Exemples en breton",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "Jules Gros, Le trésor du breton parlé (Eléments de Stylistique Trégorroise) - Troisième partie - LE STYLE POPULAIRE, 1974, page 364",
          "text": "Penn brun,\nGanet dʼal lun;\nDeiz Noz an Nedeleg\nE vo laosket da redeg.",
          "translation": "Tête de rouquin,\nné le lundi;\nle jour de la Nuit de Noël\non le laissera courir."
        }
      ],
      "glosses": [
        "Lundi."
      ],
      "id": "fr-Lun-br-name-U4T-8ASM"
    },
    {
      "categories": [
        {
          "kind": "other",
          "name": "Lexique en breton de l’astronomie",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Lune."
      ],
      "id": "fr-Lun-br-name-yPo9XTgz",
      "topics": [
        "astronomy"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\ˈlỹːn\\"
    }
  ],
  "tags": [
    "masculine"
  ],
  "word": "Lun"
}

{
  "categories": [
    "Noms propres en breton",
    "breton"
  ],
  "derived": [
    {
      "word": "Lun-Fask"
    }
  ],
  "lang": "Breton",
  "lang_code": "br",
  "pos": "name",
  "pos_title": "Nom propre",
  "senses": [
    {
      "categories": [
        "Exemples en breton"
      ],
      "examples": [
        {
          "ref": "Jules Gros, Le trésor du breton parlé (Eléments de Stylistique Trégorroise) - Troisième partie - LE STYLE POPULAIRE, 1974, page 364",
          "text": "Penn brun,\nGanet dʼal lun;\nDeiz Noz an Nedeleg\nE vo laosket da redeg.",
          "translation": "Tête de rouquin,\nné le lundi;\nle jour de la Nuit de Noël\non le laissera courir."
        }
      ],
      "glosses": [
        "Lundi."
      ]
    },
    {
      "categories": [
        "Lexique en breton de l’astronomie"
      ],
      "glosses": [
        "Lune."
      ],
      "topics": [
        "astronomy"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\ˈlỹːn\\"
    }
  ],
  "tags": [
    "masculine"
  ],
  "word": "Lun"
}