"ῥεῖθρον" meaning in Grec ancien

{
  "categories": [
    {
      "kind": "other",
      "name": "Dérivations en grec ancien",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Mots en grec ancien suffixés avec -θρον",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Noms communs en grec ancien",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Grec ancien",
      "orig": "grec ancien",
      "parents": [],
      "source": "w"
    }
  ],
  "derived": [
    {
      "lang": "Grec",
      "lang_code": "el",
      "word": "ρείθρο"
    }
  ],
  "etymology_texts": [
    "Dérivé de ῥέω, rhéô (« couler »), avec le suffixe -θρον, -thron."
  ],
  "lang": "Grec ancien",
  "lang_code": "grc",
  "pos": "noun",
  "pos_title": "Nom commun",
  "raw_tags": [
    "ῥεῖθρον, reîthron"
  ],
  "related": [
    {
      "word": "ῥέεθρον"
    }
  ],
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Wiktionnaire:Exemples manquants en grec ancien",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Cours d’eau."
      ],
      "id": "fr-ῥεῖθρον-grc-noun-2KkmpodL"
    }
  ],
  "synonyms": [
    {
      "word": "ῥόος"
    }
  ],
  "tags": [
    "neuter"
  ],
  "word": "ῥεῖθρον"
}

{
  "categories": [
    "Dérivations en grec ancien",
    "Mots en grec ancien suffixés avec -θρον",
    "Noms communs en grec ancien",
    "grec ancien"
  ],
  "derived": [
    {
      "lang": "Grec",
      "lang_code": "el",
      "word": "ρείθρο"
    }
  ],
  "etymology_texts": [
    "Dérivé de ῥέω, rhéô (« couler »), avec le suffixe -θρον, -thron."
  ],
  "lang": "Grec ancien",
  "lang_code": "grc",
  "pos": "noun",
  "pos_title": "Nom commun",
  "raw_tags": [
    "ῥεῖθρον, reîthron"
  ],
  "related": [
    {
      "word": "ῥέεθρον"
    }
  ],
  "senses": [
    {
      "categories": [
        "Wiktionnaire:Exemples manquants en grec ancien"
      ],
      "glosses": [
        "Cours d’eau."
      ]
    }
  ],
  "synonyms": [
    {
      "word": "ῥόος"
    }
  ],
  "tags": [
    "neuter"
  ],
  "word": "ῥεῖθρον"
}