"long vac" meaning in English

{
  "forms": [
    {
      "form": "long vacs",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "Long Vac",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "long vac (plural long vacs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "long vacation"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "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": "en",
          "name": "Universities",
          "orig": "en:Universities",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Clipping of long vacation."
      ],
      "id": "en-long_vac-en-noun-EllyyINg",
      "links": [
        [
          "long vacation",
          "long vacation#English"
        ]
      ],
      "qualifier": "Oxbridge slang",
      "raw_glosses": [
        "(Oxbridge slang) Clipping of long vacation."
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "clipping"
      ]
    }
  ],
  "word": "long vac"
}

{
  "forms": [
    {
      "form": "long vacs",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "Long Vac",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "long vac (plural long vacs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "long vacation"
        }
      ],
      "categories": [
        "Cambridge University slang",
        "English clippings",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Oxford University slang",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Universities"
      ],
      "glosses": [
        "Clipping of long vacation."
      ],
      "links": [
        [
          "long vacation",
          "long vacation#English"
        ]
      ],
      "qualifier": "Oxbridge slang",
      "raw_glosses": [
        "(Oxbridge slang) Clipping of long vacation."
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "clipping"
      ]
    }
  ],
  "word": "long vac"
}