"lato-" 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 des noms propres tels que Latobici, Latouici, Latto, etc.^([1])^([2]).",
    "Rapproché du vieil irlandais láth « ardeur, fureur » et du gallois llawd « chaleur, rut (de truie) »^([1])^([2])."
  ],
  "lang": "Gaulois",
  "lang_code": "gaulois",
  "pos": "noun",
  "pos_title": "Nom commun",
  "senses": [
    {
      "glosses": [
        "Ardeur, fureur."
      ],
      "id": "fr-lato--gaulois-noun-YIImjOqk"
    },
    {
      "categories": [
        {
          "kind": "other",
          "name": "Lexique en gaulois de la géographie",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Mots en gaulois de sens incertain",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Plaine."
      ],
      "id": "fr-lato--gaulois-noun-Ssxz5lUH",
      "raw_tags": [
        "Sens incertain"
      ],
      "topics": [
        "geography"
      ]
    }
  ],
  "word": "lato-"
}

{
  "categories": [
    "Mots attestés en gaulois",
    "Noms communs en gaulois",
    "gaulois"
  ],
  "etymology_texts": [
    "Mot attesté dans des noms propres tels que Latobici, Latouici, Latto, etc.^([1])^([2]).",
    "Rapproché du vieil irlandais láth « ardeur, fureur » et du gallois llawd « chaleur, rut (de truie) »^([1])^([2])."
  ],
  "lang": "Gaulois",
  "lang_code": "gaulois",
  "pos": "noun",
  "pos_title": "Nom commun",
  "senses": [
    {
      "glosses": [
        "Ardeur, fureur."
      ]
    },
    {
      "categories": [
        "Lexique en gaulois de la géographie",
        "Mots en gaulois de sens incertain"
      ],
      "glosses": [
        "Plaine."
      ],
      "raw_tags": [
        "Sens incertain"
      ],
      "topics": [
        "geography"
      ]
    }
  ],
  "word": "lato-"
}