"prototoxin" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "proto",
        "3": "toxin"
      },
      "expansion": "proto- + toxin",
      "name": "prefix"
    }
  ],
  "etymology_text": "proto- + toxin",
  "forms": [
    {
      "form": "prototoxins",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "prototoxin (plural prototoxins)",
      "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"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with proto-",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2015 October 10, “Clostridium Perfringens Epsilon Toxin Binds to Membrane Lipids and Its Cytotoxic Action Depends on Sulfatide”, in PLOS ONE, →DOI",
          "text": "Etx is synthesized as a non-active prototoxin form (proEtx) that becomes active upon proteolytic activation.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Any substance that is converted into a toxin"
      ],
      "id": "en-prototoxin-en-noun-hWn8oDxj",
      "links": [
        [
          "toxin",
          "toxin"
        ]
      ]
    }
  ],
  "word": "prototoxin"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "proto",
        "3": "toxin"
      },
      "expansion": "proto- + toxin",
      "name": "prefix"
    }
  ],
  "etymology_text": "proto- + toxin",
  "forms": [
    {
      "form": "prototoxins",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "prototoxin (plural prototoxins)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English terms prefixed with proto-",
        "English terms with quotations"
      ],
      "examples": [
        {
          "ref": "2015 October 10, “Clostridium Perfringens Epsilon Toxin Binds to Membrane Lipids and Its Cytotoxic Action Depends on Sulfatide”, in PLOS ONE, →DOI",
          "text": "Etx is synthesized as a non-active prototoxin form (proEtx) that becomes active upon proteolytic activation.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Any substance that is converted into a toxin"
      ],
      "links": [
        [
          "toxin",
          "toxin"
        ]
      ]
    }
  ],
  "word": "prototoxin"
}