"D1" meaning in English

{
  "head_templates": [
    {
      "args": {},
      "expansion": "D1",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "the highest level of intercollegiate athletics in the United States",
          "word": "NCAA Division I"
        }
      ],
      "categories": [
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Sports",
          "orig": "en:Sports",
          "parents": [
            "Human activity",
            "Human behaviour",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "_dis": "22 78",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        },
        {
          "_dis": "20 80",
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "18 82",
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "Abbreviation of NCAA Division I, the highest level of intercollegiate athletics in the United States."
      ],
      "id": "en-D1-en-name-cR3~JHUN",
      "links": [
        [
          "sports",
          "sports"
        ],
        [
          "NCAA Division I",
          "w:NCAA Division I"
        ],
        [
          "intercollegiate",
          "intercollegiate"
        ],
        [
          "athletics",
          "athletics"
        ],
        [
          "United States",
          "United States"
        ]
      ],
      "raw_glosses": [
        "(informal, sports) Abbreviation of NCAA Division I, the highest level of intercollegiate athletics in the United States."
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "informal"
      ],
      "topics": [
        "hobbies",
        "lifestyle",
        "sports"
      ]
    }
  ],
  "word": "D1"
}

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "D1 (not comparable)",
      "name": "en-adjective"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "American English",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Outstanding or extreme."
      ],
      "id": "en-D1-en-adj-u6S5ZIi~",
      "links": [
        [
          "Outstanding",
          "outstanding"
        ],
        [
          "extreme",
          "extreme"
        ]
      ],
      "raw_glosses": [
        "(US, slang) Outstanding or extreme."
      ],
      "related": [
        {
          "word": "vitamin D1"
        }
      ],
      "tags": [
        "US",
        "not-comparable",
        "slang"
      ]
    }
  ],
  "word": "D1"
}

{
  "categories": [
    "English adjectives",
    "English entries with incorrect language header",
    "English lemmas",
    "English proper nouns",
    "English terms spelled with numbers",
    "English uncomparable adjectives",
    "English uncountable nouns",
    "English words without vowels",
    "Pages with 1 entry",
    "Pages with entries"
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "D1",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "the highest level of intercollegiate athletics in the United States",
          "word": "NCAA Division I"
        }
      ],
      "categories": [
        "English abbreviations",
        "English informal terms",
        "en:Sports"
      ],
      "glosses": [
        "Abbreviation of NCAA Division I, the highest level of intercollegiate athletics in the United States."
      ],
      "links": [
        [
          "sports",
          "sports"
        ],
        [
          "NCAA Division I",
          "w:NCAA Division I"
        ],
        [
          "intercollegiate",
          "intercollegiate"
        ],
        [
          "athletics",
          "athletics"
        ],
        [
          "United States",
          "United States"
        ]
      ],
      "raw_glosses": [
        "(informal, sports) Abbreviation of NCAA Division I, the highest level of intercollegiate athletics in the United States."
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "informal"
      ],
      "topics": [
        "hobbies",
        "lifestyle",
        "sports"
      ]
    }
  ],
  "word": "D1"
}

{
  "categories": [
    "English adjectives",
    "English entries with incorrect language header",
    "English lemmas",
    "English proper nouns",
    "English terms spelled with numbers",
    "English uncomparable adjectives",
    "English uncountable nouns",
    "English words without vowels",
    "Pages with 1 entry",
    "Pages with entries"
  ],
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "D1 (not comparable)",
      "name": "en-adjective"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "related": [
    {
      "word": "vitamin D1"
    }
  ],
  "senses": [
    {
      "categories": [
        "American English",
        "English slang"
      ],
      "glosses": [
        "Outstanding or extreme."
      ],
      "links": [
        [
          "Outstanding",
          "outstanding"
        ],
        [
          "extreme",
          "extreme"
        ]
      ],
      "raw_glosses": [
        "(US, slang) Outstanding or extreme."
      ],
      "tags": [
        "US",
        "not-comparable",
        "slang"
      ]
    }
  ],
  "word": "D1"
}