"Twaddell hydrometer" meaning in English

{
  "etymology_text": "Inventor's surname.",
  "forms": [
    {
      "form": "Twaddell hydrometers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Twaddell hydrometer (plural Twaddell hydrometers)",
      "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": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "A form of hydrometer for liquids heavier than water, graduated with an arbitrary scale such that the readings when multiplied by .005 and added to unity give the specific gravity."
      ],
      "id": "en-Twaddell_hydrometer-en-noun-M4dG8mC-",
      "links": [
        [
          "hydrometer",
          "hydrometer"
        ],
        [
          "liquid",
          "liquid"
        ],
        [
          "water",
          "water"
        ],
        [
          "reading",
          "reading"
        ],
        [
          "unity",
          "unity"
        ],
        [
          "specific gravity",
          "specific gravity"
        ]
      ]
    }
  ],
  "word": "Twaddell hydrometer"
}

{
  "etymology_text": "Inventor's surname.",
  "forms": [
    {
      "form": "Twaddell hydrometers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Twaddell hydrometer (plural Twaddell hydrometers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English eponyms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "A form of hydrometer for liquids heavier than water, graduated with an arbitrary scale such that the readings when multiplied by .005 and added to unity give the specific gravity."
      ],
      "links": [
        [
          "hydrometer",
          "hydrometer"
        ],
        [
          "liquid",
          "liquid"
        ],
        [
          "water",
          "water"
        ],
        [
          "reading",
          "reading"
        ],
        [
          "unity",
          "unity"
        ],
        [
          "specific gravity",
          "specific gravity"
        ]
      ]
    }
  ],
  "word": "Twaddell hydrometer"
}