"middler" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "middle",
        "3": "er"
      },
      "expansion": "middle + -er",
      "name": "suffix"
    }
  ],
  "etymology_text": "From middle + -er.",
  "forms": [
    {
      "form": "middlers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "middler (plural middlers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "_dis": "77 19 4",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "58 32 10",
          "kind": "other",
          "name": "English terms suffixed with -er",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "71 19 9",
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "85 10 5",
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "One of a middle or intermediate class in some schools and seminaries."
      ],
      "id": "en-middler-en-noun-FfcIYIZi"
    },
    {
      "glosses": [
        "A pupil at middle school."
      ],
      "id": "en-middler-en-noun-94jLmhx9",
      "links": [
        [
          "middle school",
          "middle school"
        ]
      ]
    },
    {
      "glosses": [
        "Someone or something in the middle."
      ],
      "id": "en-middler-en-noun-Yza5GtLG",
      "links": [
        [
          "middle",
          "middle"
        ]
      ]
    }
  ],
  "word": "middler"
}

{
  "categories": [
    "English countable nouns",
    "English entries with incorrect language header",
    "English lemmas",
    "English nouns",
    "English terms suffixed with -er",
    "Pages with 1 entry",
    "Pages with entries"
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "middle",
        "3": "er"
      },
      "expansion": "middle + -er",
      "name": "suffix"
    }
  ],
  "etymology_text": "From middle + -er.",
  "forms": [
    {
      "form": "middlers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "middler (plural middlers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "glosses": [
        "One of a middle or intermediate class in some schools and seminaries."
      ]
    },
    {
      "glosses": [
        "A pupil at middle school."
      ],
      "links": [
        [
          "middle school",
          "middle school"
        ]
      ]
    },
    {
      "glosses": [
        "Someone or something in the middle."
      ],
      "links": [
        [
          "middle",
          "middle"
        ]
      ]
    }
  ],
  "word": "middler"
}