"protosome" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "proto-",
        "3": "-some"
      },
      "expansion": "proto- + -some",
      "name": "af"
    }
  ],
  "etymology_text": "From proto- + -some.",
  "forms": [
    {
      "form": "protosomes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "protosome (plural protosomes)",
      "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"
        },
        {
          "kind": "other",
          "name": "English terms suffixed with -some",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        }
      ],
      "derived": [
        {
          "word": "protosomal"
        }
      ],
      "glosses": [
        "The proboscis of hemichordate animals."
      ],
      "id": "en-protosome-en-noun-vzTjgYbT",
      "links": [
        [
          "proboscis",
          "proboscis"
        ],
        [
          "hemichordate",
          "hemichordate"
        ],
        [
          "animal",
          "animal"
        ]
      ],
      "related": [
        {
          "word": "mesosome"
        },
        {
          "word": "metasome"
        }
      ]
    }
  ],
  "word": "protosome"
}

{
  "derived": [
    {
      "word": "protosomal"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "proto-",
        "3": "-some"
      },
      "expansion": "proto- + -some",
      "name": "af"
    }
  ],
  "etymology_text": "From proto- + -some.",
  "forms": [
    {
      "form": "protosomes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "protosome (plural protosomes)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "mesosome"
    },
    {
      "word": "metasome"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English terms prefixed with proto-",
        "English terms suffixed with -some",
        "Pages with 1 entry"
      ],
      "glosses": [
        "The proboscis of hemichordate animals."
      ],
      "links": [
        [
          "proboscis",
          "proboscis"
        ],
        [
          "hemichordate",
          "hemichordate"
        ],
        [
          "animal",
          "animal"
        ]
      ]
    }
  ],
  "word": "protosome"
}