"water hen" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "water",
        "3": "hen"
      },
      "expansion": "water + hen",
      "name": "compound"
    }
  ],
  "etymology_text": "From water + hen.",
  "forms": [
    {
      "form": "water hens",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "water hen (plural water hens)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "British English",
          "parents": [],
          "source": "w"
        },
        {
          "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"
        },
        {
          "kind": "lifeform",
          "langcode": "en",
          "name": "Rallids",
          "orig": "en:Rallids",
          "parents": [
            "Gruiforms",
            "Freshwater birds",
            "Birds",
            "Vertebrates",
            "Chordates",
            "Animals",
            "Lifeforms",
            "All topics",
            "Life",
            "Fundamental",
            "Nature"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "The moorhen."
      ],
      "id": "en-water_hen-en-noun-Jmo82cc7",
      "links": [
        [
          "moorhen",
          "moorhen"
        ]
      ],
      "raw_glosses": [
        "(UK) The moorhen."
      ],
      "tags": [
        "UK"
      ]
    }
  ],
  "word": "water hen"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "water",
        "3": "hen"
      },
      "expansion": "water + hen",
      "name": "compound"
    }
  ],
  "etymology_text": "From water + hen.",
  "forms": [
    {
      "form": "water hens",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "water hen (plural water hens)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "British English",
        "English compound terms",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Rallids"
      ],
      "glosses": [
        "The moorhen."
      ],
      "links": [
        [
          "moorhen",
          "moorhen"
        ]
      ],
      "raw_glosses": [
        "(UK) The moorhen."
      ],
      "tags": [
        "UK"
      ]
    }
  ],
  "word": "water hen"
}