"Theseion" meaning in English

{
  "etymology_text": "So called under the mistaken assumption that it housed the remains of the Athenian hero Theseus.",
  "forms": [
    {
      "form": "the Theseion",
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "Theseum",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "head": "the Theseion"
      },
      "expansion": "the Theseion",
      "name": "en-prop"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Synonym of Hephaestaeum (“the Temple of Hephaestus in Athens”)"
      ],
      "id": "en-Theseion-en-name-XfKpdaRF",
      "links": [
        [
          "Hephaestaeum",
          "Hephaestaeum#English"
        ]
      ],
      "synonyms": [
        {
          "extra": "the Temple of Hephaestus in Athens",
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "Hephaestaeum"
        }
      ]
    }
  ],
  "word": "Theseion"
}

{
  "etymology_text": "So called under the mistaken assumption that it housed the remains of the Athenian hero Theseus.",
  "forms": [
    {
      "form": "the Theseion",
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "Theseum",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "head": "the Theseion"
      },
      "expansion": "the Theseion",
      "name": "en-prop"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English eponyms",
        "English lemmas",
        "English proper nouns",
        "English uncountable nouns",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "Synonym of Hephaestaeum (“the Temple of Hephaestus in Athens”)"
      ],
      "links": [
        [
          "Hephaestaeum",
          "Hephaestaeum#English"
        ]
      ],
      "synonyms": [
        {
          "extra": "the Temple of Hephaestus in Athens",
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "Hephaestaeum"
        }
      ]
    }
  ],
  "word": "Theseion"
}