"isto" meaning in Esperanto

{
  "etymology_templates": [
    {
      "args": {
        "1": "eo",
        "2": "-isto",
        "gloss": "person of profession concerned with"
      },
      "expansion": "Back-formation from -isto (“person of profession concerned with”)",
      "name": "back-form"
    }
  ],
  "etymology_text": "Back-formation from -isto (“person of profession concerned with”); hence literally “an ‘ist’”.",
  "forms": [
    {
      "form": "iston",
      "tags": [
        "accusative",
        "singular"
      ]
    },
    {
      "form": "istoj",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "istojn",
      "tags": [
        "accusative",
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "isto (accusative singular iston, plural istoj, accusative plural istojn)",
      "name": "eo-head"
    }
  ],
  "lang": "Esperanto",
  "lang_code": "eo",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Esperanto back-formations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Esperanto entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Esperanto entries with language name categories using raw markup",
          "parents": [
            "Entries with language name categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Esperanto terms suffixed with -isto",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "english": "Call a professional.",
          "text": "Voku iston.",
          "type": "example"
        }
      ],
      "glosses": [
        "A professional, a person who belongs to a profession."
      ],
      "id": "en-isto-eo-noun-WK4o5jJy",
      "links": [
        [
          "professional",
          "professional"
        ],
        [
          "profession",
          "profession"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "rhymes": "-isto"
    },
    {
      "audio": "LL-Q143 (epo)-Robin van der Vliet-isto.wav",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/e/e1/LL-Q143_%28epo%29-Robin_van_der_Vliet-isto.wav/LL-Q143_%28epo%29-Robin_van_der_Vliet-isto.wav.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/e/e1/LL-Q143_%28epo%29-Robin_van_der_Vliet-isto.wav/LL-Q143_%28epo%29-Robin_van_der_Vliet-isto.wav.ogg",
      "text": "Audio"
    }
  ],
  "word": "isto"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "eo",
        "2": "-isto",
        "gloss": "person of profession concerned with"
      },
      "expansion": "Back-formation from -isto (“person of profession concerned with”)",
      "name": "back-form"
    }
  ],
  "etymology_text": "Back-formation from -isto (“person of profession concerned with”); hence literally “an ‘ist’”.",
  "forms": [
    {
      "form": "iston",
      "tags": [
        "accusative",
        "singular"
      ]
    },
    {
      "form": "istoj",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "istojn",
      "tags": [
        "accusative",
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "isto (accusative singular iston, plural istoj, accusative plural istojn)",
      "name": "eo-head"
    }
  ],
  "lang": "Esperanto",
  "lang_code": "eo",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Esperanto back-formations",
        "Esperanto entries with incorrect language header",
        "Esperanto entries with language name categories using raw markup",
        "Esperanto lemmas",
        "Esperanto nouns",
        "Esperanto terms suffixed with -isto",
        "Esperanto terms with audio links",
        "Esperanto terms with usage examples",
        "Rhymes:Esperanto/isto"
      ],
      "examples": [
        {
          "english": "Call a professional.",
          "text": "Voku iston.",
          "type": "example"
        }
      ],
      "glosses": [
        "A professional, a person who belongs to a profession."
      ],
      "links": [
        [
          "professional",
          "professional"
        ],
        [
          "profession",
          "profession"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "rhymes": "-isto"
    },
    {
      "audio": "LL-Q143 (epo)-Robin van der Vliet-isto.wav",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/e/e1/LL-Q143_%28epo%29-Robin_van_der_Vliet-isto.wav/LL-Q143_%28epo%29-Robin_van_der_Vliet-isto.wav.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/e/e1/LL-Q143_%28epo%29-Robin_van_der_Vliet-isto.wav/LL-Q143_%28epo%29-Robin_van_der_Vliet-isto.wav.ogg",
      "text": "Audio"
    }
  ],
  "word": "isto"
}