"前方後円墳" meaning in Japanese

{
  "forms": [
    {
      "form": "前方後円墳 ^",
      "ruby": [
        [
          "前方後円墳",
          "ぜんぽうこえんふん"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "zenpōkoenfun",
      "tags": [
        "romanization"
      ]
    },
    {
      "form": "zenpaukouwenfun",
      "tags": [
        "romanization"
      ]
    },
    {
      "form": "ぜんぱうこうゑんふん",
      "roman": "zenpaukouwenfun",
      "tags": [
        "hiragana",
        "historical"
      ]
    },
    {
      "form": "前方後圓墳",
      "tags": [
        "alternative",
        "kanji",
        "kyūjitai"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "ぜんぽうこえんふん",
        "hhira": "ぜんぱうこうゑんふん"
      },
      "expansion": "前方後円墳(ぜんぽうこえんふん) • (zenpōkoenfun) ^(←ぜんぱうこうゑんふん (zenpaukouwenfun)?)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Japanese entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese links with redundant alt parameters",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese links with redundant wikilinks",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms read with on'yomi",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with 5 kanji",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with non-redundant non-automated sortkeys",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with redundant sortkeys",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with rendaku",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "langcode": "ja",
          "name": "Archaeology",
          "orig": "ja:Archaeology",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "keyhole tomb; a tomb with a square mound in the fore with a round mound behind, often moated and generally monumental"
      ],
      "id": "en-前方後円墳-ja-noun-riFcSkTZ",
      "links": [
        [
          "archaeology",
          "archaeology"
        ]
      ],
      "raw_glosses": [
        "(archaeology) keyhole tomb; a tomb with a square mound in the fore with a round mound behind, often moated and generally monumental"
      ],
      "topics": [
        "archaeology",
        "history",
        "human-sciences",
        "sciences"
      ]
    }
  ],
  "word": "前方後円墳"
}

{
  "forms": [
    {
      "form": "前方後円墳 ^",
      "ruby": [
        [
          "前方後円墳",
          "ぜんぽうこえんふん"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "zenpōkoenfun",
      "tags": [
        "romanization"
      ]
    },
    {
      "form": "zenpaukouwenfun",
      "tags": [
        "romanization"
      ]
    },
    {
      "form": "ぜんぱうこうゑんふん",
      "roman": "zenpaukouwenfun",
      "tags": [
        "hiragana",
        "historical"
      ]
    },
    {
      "form": "前方後圓墳",
      "tags": [
        "alternative",
        "kanji",
        "kyūjitai"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "ぜんぽうこえんふん",
        "hhira": "ぜんぱうこうゑんふん"
      },
      "expansion": "前方後円墳(ぜんぽうこえんふん) • (zenpōkoenfun) ^(←ぜんぱうこうゑんふん (zenpaukouwenfun)?)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Japanese entries with incorrect language header",
        "Japanese lemmas",
        "Japanese links with redundant alt parameters",
        "Japanese links with redundant wikilinks",
        "Japanese nouns",
        "Japanese terms historically spelled with ゑ",
        "Japanese terms read with on'yomi",
        "Japanese terms spelled with first grade kanji",
        "Japanese terms spelled with second grade kanji",
        "Japanese terms spelled with secondary school kanji",
        "Japanese terms spelled with 円 read as えん",
        "Japanese terms spelled with 前 read as ぜん",
        "Japanese terms spelled with 墳 read as ふん",
        "Japanese terms spelled with 後 read as こう",
        "Japanese terms spelled with 方 read as ほう",
        "Japanese terms with 5 kanji",
        "Japanese terms with non-redundant non-automated sortkeys",
        "Japanese terms with redundant sortkeys",
        "Japanese terms with rendaku",
        "Pages with 1 entry",
        "Pages with entries",
        "ja:Archaeology"
      ],
      "glosses": [
        "keyhole tomb; a tomb with a square mound in the fore with a round mound behind, often moated and generally monumental"
      ],
      "links": [
        [
          "archaeology",
          "archaeology"
        ]
      ],
      "raw_glosses": [
        "(archaeology) keyhole tomb; a tomb with a square mound in the fore with a round mound behind, often moated and generally monumental"
      ],
      "topics": [
        "archaeology",
        "history",
        "human-sciences",
        "sciences"
      ]
    }
  ],
  "word": "前方後円墳"
}