"hiruko erregela" meaning in Basque

{
  "categories": [
    {
      "kind": "other",
      "name": "Compositions en basque",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Locutions nominales en basque",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Basque",
      "orig": "basque",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_texts": [
    "Composé de hiru, -ko et erregela."
  ],
  "lang": "Basque",
  "lang_code": "eu",
  "pos": "noun",
  "pos_title": "Locution nominale",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Lexique en basque des mathématiques",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Wiktionnaire:Exemples manquants en basque",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Règle de trois."
      ],
      "id": "fr-hiruko_erregela-eu-noun-m2Dl2JhB",
      "topics": [
        "mathematics"
      ]
    }
  ],
  "word": "hiruko erregela"
}

{
  "categories": [
    "Compositions en basque",
    "Locutions nominales en basque",
    "basque"
  ],
  "etymology_texts": [
    "Composé de hiru, -ko et erregela."
  ],
  "lang": "Basque",
  "lang_code": "eu",
  "pos": "noun",
  "pos_title": "Locution nominale",
  "senses": [
    {
      "categories": [
        "Lexique en basque des mathématiques",
        "Wiktionnaire:Exemples manquants en basque"
      ],
      "glosses": [
        "Règle de trois."
      ],
      "topics": [
        "mathematics"
      ]
    }
  ],
  "word": "hiruko erregela"
}