"Pre-U" meaning in English

{
  "etymology_text": "Short for preuniversity.",
  "forms": [
    {
      "form": "Pre-Us",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "head": "Pre-U"
      },
      "expansion": "Pre-U (plural Pre-Us)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "British English",
          "parents": [],
          "source": "w"
        },
        {
          "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"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Education",
          "orig": "en:Education",
          "parents": [
            "Society",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A school-leaving qualification that is an alternative to A levels."
      ],
      "id": "en-Pre-U-en-noun-DnK5q6m4",
      "links": [
        [
          "education",
          "education"
        ],
        [
          "A level",
          "A level"
        ]
      ],
      "raw_glosses": [
        "(UK, education) A school-leaving qualification that is an alternative to A levels."
      ],
      "tags": [
        "UK"
      ],
      "topics": [
        "education"
      ],
      "wikipedia": [
        "Pre-U"
      ]
    }
  ],
  "word": "Pre-U"
}

{
  "etymology_text": "Short for preuniversity.",
  "forms": [
    {
      "form": "Pre-Us",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "head": "Pre-U"
      },
      "expansion": "Pre-U (plural Pre-Us)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "British English",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Education"
      ],
      "glosses": [
        "A school-leaving qualification that is an alternative to A levels."
      ],
      "links": [
        [
          "education",
          "education"
        ],
        [
          "A level",
          "A level"
        ]
      ],
      "raw_glosses": [
        "(UK, education) A school-leaving qualification that is an alternative to A levels."
      ],
      "tags": [
        "UK"
      ],
      "topics": [
        "education"
      ],
      "wikipedia": [
        "Pre-U"
      ]
    }
  ],
  "word": "Pre-U"
}