"tanno-" meaning in Gaulois

{
  "categories": [
    {
      "kind": "other",
      "name": "Mots attestés en gaulois",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Noms communs en gaulois",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Gaulois",
      "orig": "gaulois",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_texts": [
    "Mot attesté dans les noms propres tels que Tannonius, Tannogilum, etc.^([1])^([2]).",
    "À comparer avec les mots tann en breton et tannen en vieux cornique (sens identique)."
  ],
  "lang": "Gaulois",
  "lang_code": "gaulois",
  "pos": "noun",
  "pos_title": "Nom commun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Arbres en gaulois",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Chêne vert."
      ],
      "id": "fr-tanno--gaulois-noun-xfNy9Z7b",
      "topics": [
        "botany"
      ]
    }
  ],
  "word": "tanno-"
}

{
  "categories": [
    "Mots attestés en gaulois",
    "Noms communs en gaulois",
    "gaulois"
  ],
  "etymology_texts": [
    "Mot attesté dans les noms propres tels que Tannonius, Tannogilum, etc.^([1])^([2]).",
    "À comparer avec les mots tann en breton et tannen en vieux cornique (sens identique)."
  ],
  "lang": "Gaulois",
  "lang_code": "gaulois",
  "pos": "noun",
  "pos_title": "Nom commun",
  "senses": [
    {
      "categories": [
        "Arbres en gaulois"
      ],
      "glosses": [
        "Chêne vert."
      ],
      "topics": [
        "botany"
      ]
    }
  ],
  "word": "tanno-"
}