"potamologist" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "potamology",
        "3": "ist"
      },
      "expansion": "potamology + -ist",
      "name": "suffix"
    }
  ],
  "etymology_text": "potamology + -ist",
  "forms": [
    {
      "form": "potamologists",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "potamologist (plural potamologists)",
      "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 suffixed with -ist",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Scientists",
          "orig": "en:Scientists",
          "parents": [
            "Occupations",
            "Sciences",
            "People",
            "Work",
            "All topics",
            "Human",
            "Human activity",
            "Fundamental",
            "Human behaviour"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "One who studies rivers."
      ],
      "id": "en-potamologist-en-noun-rBXzkgb5",
      "links": [
        [
          "river",
          "river"
        ]
      ]
    }
  ],
  "word": "potamologist"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "potamology",
        "3": "ist"
      },
      "expansion": "potamology + -ist",
      "name": "suffix"
    }
  ],
  "etymology_text": "potamology + -ist",
  "forms": [
    {
      "form": "potamologists",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "potamologist (plural potamologists)",
      "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 suffixed with -ist",
        "en:Scientists"
      ],
      "glosses": [
        "One who studies rivers."
      ],
      "links": [
        [
          "river",
          "river"
        ]
      ]
    }
  ],
  "word": "potamologist"
}