"μηδενός" meaning in Greek

{
  "forms": [
    {
      "form": "midenós",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "numeral"
      },
      "expansion": "μηδενός • (midenós)",
      "name": "head"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "num",
  "senses": [
    {
      "categories": [
        {
          "kind": "topical",
          "name": "Greek cardinal numbers",
          "parents": [
            "Cardinal numbers",
            "Numbers",
            "All topics",
            "Terms by semantic function",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Greek entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "extra": "(midén), (zero)",
          "word": "μηδέν"
        }
      ],
      "glosses": [
        "genitive of μηδέν (midén), (zero)."
      ],
      "id": "en-μηδενός-el-num-tESiFroX",
      "links": [
        [
          "μηδέν",
          "μηδέν#Greek"
        ],
        [
          "zero",
          "zero"
        ]
      ],
      "related": [
        {
          "word": "Greek number and measurement"
        }
      ],
      "tags": [
        "form-of",
        "genitive"
      ]
    }
  ],
  "word": "μηδενός"
}

{
  "forms": [
    {
      "form": "midenós",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "numeral"
      },
      "expansion": "μηδενός • (midenós)",
      "name": "head"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "num",
  "related": [
    {
      "word": "Greek number and measurement"
    }
  ],
  "senses": [
    {
      "categories": [
        "Greek cardinal numbers",
        "Greek entries with incorrect language header",
        "Greek lemmas",
        "Greek numerals"
      ],
      "form_of": [
        {
          "extra": "(midén), (zero)",
          "word": "μηδέν"
        }
      ],
      "glosses": [
        "genitive of μηδέν (midén), (zero)."
      ],
      "links": [
        [
          "μηδέν",
          "μηδέν#Greek"
        ],
        [
          "zero",
          "zero"
        ]
      ],
      "tags": [
        "form-of",
        "genitive"
      ]
    }
  ],
  "word": "μηδενός"
}