"mad professor" meaning in English

{
  "forms": [
    {
      "form": "mad professors",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "mad professor (plural mad professors)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2010, Monte Dwyer, Red in the Centre: Through a Crooked Lens, Monyer Pty Ltd, page 62",
          "text": "He's got that mad professor look about him, and you can imagine how a minor detail like whether the car worked or not would have escaped his attention.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "mad scientist"
      ],
      "id": "en-mad_professor-en-noun-VkKSeowG",
      "links": [
        [
          "mad scientist",
          "mad scientist"
        ]
      ]
    }
  ],
  "word": "mad professor"
}

{
  "forms": [
    {
      "form": "mad professors",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "mad professor (plural mad professors)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations"
      ],
      "examples": [
        {
          "ref": "2010, Monte Dwyer, Red in the Centre: Through a Crooked Lens, Monyer Pty Ltd, page 62",
          "text": "He's got that mad professor look about him, and you can imagine how a minor detail like whether the car worked or not would have escaped his attention.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "mad scientist"
      ],
      "links": [
        [
          "mad scientist",
          "mad scientist"
        ]
      ]
    }
  ],
  "word": "mad professor"
}