"nighty night" meaning in English

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      "expansion": "nighty night",
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  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
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          "name": "English cognate expressions",
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      "glosses": [
        "Good night."
      ],
      "id": "en-nighty_night-en-phrase-u8iZ8rjX",
      "links": [
        [
          "childish",
          "childish"
        ],
        [
          "Good night",
          "good night"
        ]
      ],
      "raw_glosses": [
        "(colloquial, usually childish) Good night."
      ],
      "synonyms": [
        {
          "word": "nighty-night"
        }
      ],
      "tags": [
        "childish",
        "colloquial",
        "usually"
      ],
      "translations": [
        {
          "code": "ca",
          "lang": "Catalan",
          "sense": "a farewell",
          "word": "nanit"
        },
        {
          "code": "ru",
          "lang": "Russian",
          "roman": "spóki nóki",
          "sense": "a farewell",
          "word": "спо́ки но́ки"
        }
      ]
    }
  ],
  "word": "nighty night"
}

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      "expansion": "nighty night",
      "name": "head"
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  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
    {
      "categories": [
        "English childish terms",
        "English cognate expressions",
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      "glosses": [
        "Good night."
      ],
      "links": [
        [
          "childish",
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        [
          "Good night",
          "good night"
        ]
      ],
      "raw_glosses": [
        "(colloquial, usually childish) Good night."
      ],
      "tags": [
        "childish",
        "colloquial",
        "usually"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "nighty-night"
    }
  ],
  "translations": [
    {
      "code": "ca",
      "lang": "Catalan",
      "sense": "a farewell",
      "word": "nanit"
    },
    {
      "code": "ru",
      "lang": "Russian",
      "roman": "spóki nóki",
      "sense": "a farewell",
      "word": "спо́ки но́ки"
    }
  ],
  "word": "nighty night"
}