"upper ten thousand" meaning in English

{
  "etymology_text": "Coined in the 1800s by American poet and author Nathaniel Parker Willis.",
  "head_templates": [
    {
      "args": {
        "1": "p"
      },
      "expansion": "upper ten thousand pl (plural only)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English pluralia tantum",
          "parents": [
            "Pluralia tantum",
            "Nouns",
            "Lemmas"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "The ten thousand people, more or less, who are highest in position or wealth; the upper class; the aristocracy."
      ],
      "id": "en-upper_ten_thousand-en-noun-Xqitawvr",
      "links": [
        [
          "position",
          "position"
        ],
        [
          "wealth",
          "wealth"
        ],
        [
          "upper class",
          "upper class"
        ],
        [
          "aristocracy",
          "aristocracy"
        ]
      ],
      "raw_glosses": [
        "(dated, colloquial) The ten thousand people, more or less, who are highest in position or wealth; the upper class; the aristocracy."
      ],
      "synonyms": [
        {
          "word": "upper ten"
        }
      ],
      "tags": [
        "colloquial",
        "dated",
        "plural",
        "plural-only"
      ],
      "wikipedia": [
        "upper ten thousand"
      ]
    }
  ],
  "word": "upper ten thousand"
}

{
  "etymology_text": "Coined in the 1800s by American poet and author Nathaniel Parker Willis.",
  "head_templates": [
    {
      "args": {
        "1": "p"
      },
      "expansion": "upper ten thousand pl (plural only)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English colloquialisms",
        "English dated terms",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English pluralia tantum"
      ],
      "glosses": [
        "The ten thousand people, more or less, who are highest in position or wealth; the upper class; the aristocracy."
      ],
      "links": [
        [
          "position",
          "position"
        ],
        [
          "wealth",
          "wealth"
        ],
        [
          "upper class",
          "upper class"
        ],
        [
          "aristocracy",
          "aristocracy"
        ]
      ],
      "raw_glosses": [
        "(dated, colloquial) The ten thousand people, more or less, who are highest in position or wealth; the upper class; the aristocracy."
      ],
      "tags": [
        "colloquial",
        "dated",
        "plural",
        "plural-only"
      ],
      "wikipedia": [
        "upper ten thousand"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "upper ten"
    }
  ],
  "word": "upper ten thousand"
}