"0-dark-hundred" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "0-dark-hundred (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "American 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": "topical",
          "langcode": "en",
          "name": "Times of day",
          "orig": "en:Times of day",
          "parents": [
            "Periodic occurrences",
            "Timekeeping",
            "Time",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1996, Richard Marcinko, John Weisman, Green Team: Rogue Warrior III, page 4:",
          "text": "Which is precisely why I'd volunteered as point man on this little jaunt, prowling and growling up the unlit stairwell of a Cairo slum at 0-dark-hundred to catch my quarry napping on his bedroll.",
          "type": "quote"
        },
        {
          "ref": "2011, Diane L. Sheridan, Don't Forget the Flippin' E: A Memoir, page 290:",
          "text": "It's late, and we have to get up at 0-dark-hundred to got to Paris in the AM.",
          "type": "quote"
        }
      ],
      "glosses": [
        "An otherwise unspecified time of night; some time when it is dark out."
      ],
      "id": "en-0-dark-hundred-en-noun-2yYQThVX",
      "links": [
        [
          "military",
          "military"
        ],
        [
          "slang",
          "slang"
        ]
      ],
      "raw_glosses": [
        "(chiefly US military slang) An otherwise unspecified time of night; some time when it is dark out."
      ],
      "related": [
        {
          "word": "0-dark-thirty"
        },
        {
          "word": "dark thirty"
        },
        {
          "word": "oh dark hundred"
        },
        {
          "word": "oh dark thirty"
        },
        {
          "word": "zero dark thirty"
        },
        {
          "word": "beer o'clock"
        }
      ],
      "synonyms": [
        {
          "word": "stupid o'clock"
        },
        {
          "word": "wee small hours"
        },
        {
          "word": "early morning"
        }
      ],
      "tags": [
        "US",
        "slang",
        "uncountable"
      ],
      "topics": [
        "government",
        "military",
        "politics",
        "war"
      ]
    }
  ],
  "word": "0-dark-hundred"
}

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "0-dark-hundred (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "0-dark-thirty"
    },
    {
      "word": "dark thirty"
    },
    {
      "word": "oh dark hundred"
    },
    {
      "word": "oh dark thirty"
    },
    {
      "word": "zero dark thirty"
    },
    {
      "word": "beer o'clock"
    }
  ],
  "senses": [
    {
      "categories": [
        "American English",
        "English entries with incorrect language header",
        "English lemmas",
        "English military slang",
        "English multiword terms",
        "English nouns",
        "English terms spelled with numbers",
        "English terms with quotations",
        "English uncountable nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Times of day"
      ],
      "examples": [
        {
          "ref": "1996, Richard Marcinko, John Weisman, Green Team: Rogue Warrior III, page 4:",
          "text": "Which is precisely why I'd volunteered as point man on this little jaunt, prowling and growling up the unlit stairwell of a Cairo slum at 0-dark-hundred to catch my quarry napping on his bedroll.",
          "type": "quote"
        },
        {
          "ref": "2011, Diane L. Sheridan, Don't Forget the Flippin' E: A Memoir, page 290:",
          "text": "It's late, and we have to get up at 0-dark-hundred to got to Paris in the AM.",
          "type": "quote"
        }
      ],
      "glosses": [
        "An otherwise unspecified time of night; some time when it is dark out."
      ],
      "links": [
        [
          "military",
          "military"
        ],
        [
          "slang",
          "slang"
        ]
      ],
      "raw_glosses": [
        "(chiefly US military slang) An otherwise unspecified time of night; some time when it is dark out."
      ],
      "tags": [
        "US",
        "slang",
        "uncountable"
      ],
      "topics": [
        "government",
        "military",
        "politics",
        "war"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "stupid o'clock"
    },
    {
      "word": "wee small hours"
    },
    {
      "word": "early morning"
    }
  ],
  "word": "0-dark-hundred"
}