"9th grader" meaning in English

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        "2": "9th grade",
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      "expansion": "9th grade + -er",
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  "etymology_text": "9th grade + -er",
  "forms": [
    {
      "form": "9th graders",
      "tags": [
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      "expansion": "9th grader (plural 9th graders)",
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
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        {
          "word": "ninth grader"
        }
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        {
          "kind": "topical",
          "langcode": "en",
          "name": "Education",
          "orig": "en:Education",
          "parents": [
            "Society",
            "All topics",
            "Fundamental"
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      ],
      "glosses": [
        "Alternative spelling of ninth grader"
      ],
      "id": "en-9th_grader-en-noun-kRgph~kb",
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  "word": "9th grader"
}

{
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    {
      "args": {
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        "2": "9th grade",
        "3": "er",
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    }
  ],
  "etymology_text": "9th grade + -er",
  "forms": [
    {
      "form": "9th graders",
      "tags": [
        "plural"
      ]
    }
  ],
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  "lang_code": "en",
  "pos": "noun",
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          "word": "ninth grader"
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      "glosses": [
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  "word": "9th grader"
}