"bissextile year" meaning in English

{
  "etymology_text": "From bissextile + year.",
  "forms": [
    {
      "form": "bissextile years",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "bissextile year (plural bissextile years)",
      "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"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Calendar",
          "orig": "en:Calendar",
          "parents": [
            "Timekeeping",
            "Time",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Years",
          "orig": "en:Years",
          "parents": [
            "Periodic occurrences",
            "Time",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "a year with an extra day, a leap year"
      ],
      "id": "en-bissextile_year-en-noun-lcChoED0",
      "links": [
        [
          "leap year",
          "leap year"
        ]
      ],
      "related": [
        {
          "word": "bissextile"
        },
        {
          "word": "bissextile month"
        },
        {
          "word": "intercalate"
        },
        {
          "word": "leap day"
        },
        {
          "word": "leap year"
        }
      ]
    }
  ],
  "word": "bissextile year"
}

{
  "etymology_text": "From bissextile + year.",
  "forms": [
    {
      "form": "bissextile years",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "bissextile year (plural bissextile years)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "bissextile"
    },
    {
      "word": "bissextile month"
    },
    {
      "word": "intercalate"
    },
    {
      "word": "leap day"
    },
    {
      "word": "leap year"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms derived from Latin",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Calendar",
        "en:Years"
      ],
      "glosses": [
        "a year with an extra day, a leap year"
      ],
      "links": [
        [
          "leap year",
          "leap year"
        ]
      ]
    }
  ],
  "word": "bissextile year"
}