"ἀλάστορσιν" meaning in Ancient Greek

{
  "forms": [
    {
      "form": "alástorsin",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m",
        "g2": "f"
      },
      "expansion": "ἀλάστορσιν • (alástorsin) m or f",
      "name": "grc-noun form"
    }
  ],
  "lang": "Ancient Greek",
  "lang_code": "grc",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Ancient Greek entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Ancient Greek terms with movable nu",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "extra": "(alástōr) with movable nu",
          "word": "ἀλάστωρ"
        }
      ],
      "glosses": [
        "dative plural of ἀλάστωρ (alástōr) with movable nu"
      ],
      "id": "en-ἀλάστορσιν-grc-noun-o4QRq4LZ",
      "links": [
        [
          "ἀλάστωρ",
          "ἀλάστωρ#Ancient_Greek"
        ],
        [
          "movable nu",
          "movable nu#English"
        ]
      ],
      "tags": [
        "dative",
        "form-of",
        "plural"
      ]
    }
  ],
  "word": "ἀλάστορσιν"
}

{
  "forms": [
    {
      "form": "alástorsin",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m",
        "g2": "f"
      },
      "expansion": "ἀλάστορσιν • (alástorsin) m or f",
      "name": "grc-noun form"
    }
  ],
  "lang": "Ancient Greek",
  "lang_code": "grc",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Ancient Greek entries with incorrect language header",
        "Ancient Greek non-lemma forms",
        "Ancient Greek noun forms",
        "Ancient Greek proparoxytone terms",
        "Ancient Greek terms with movable nu",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "form_of": [
        {
          "extra": "(alástōr) with movable nu",
          "word": "ἀλάστωρ"
        }
      ],
      "glosses": [
        "dative plural of ἀλάστωρ (alástōr) with movable nu"
      ],
      "links": [
        [
          "ἀλάστωρ",
          "ἀλάστωρ#Ancient_Greek"
        ],
        [
          "movable nu",
          "movable nu#English"
        ]
      ],
      "tags": [
        "dative",
        "form-of",
        "plural"
      ]
    }
  ],
  "word": "ἀλάστορσιν"
}