"pentennial" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "grc",
        "3": "πέντε",
        "4": "",
        "5": "five"
      },
      "expansion": "Ancient Greek πέντε (pénte, “five”)",
      "name": "uder"
    },
    {
      "args": {
        "1": "en",
        "2": "la",
        "3": "annus",
        "4": "",
        "5": "year"
      },
      "expansion": "Latin annus (“year”)",
      "name": "uder"
    },
    {
      "args": {
        "1": "en",
        "2": "",
        "3": "ial"
      },
      "expansion": "+ -ial",
      "name": "suffix"
    }
  ],
  "etymology_text": "From Ancient Greek πέντε (pénte, “five”) + Latin annus (“year”) + -ial.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "pentennial (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
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          "source": "w"
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          "parents": [
            "Entries with topic categories using raw markup",
            "Entry maintenance"
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          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms suffixed with -ial",
          "parents": [],
          "source": "w"
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          "kind": "other",
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          "parents": [
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        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Five",
          "orig": "en:Five",
          "parents": [
            "Numbers",
            "All topics",
            "Terms by semantic function",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "The family had plans to attend the pentennial reunion.",
          "type": "example"
        }
      ],
      "glosses": [
        "Synonym of quinquennial: occurring every five years."
      ],
      "id": "en-pentennial-en-adj-DXL-D7F2",
      "links": [
        [
          "quinquennial",
          "quinquennial#English"
        ],
        [
          "occur",
          "occur"
        ],
        [
          "every",
          "every"
        ],
        [
          "five",
          "five"
        ],
        [
          "year",
          "year"
        ]
      ],
      "raw_glosses": [
        "(rare) Synonym of quinquennial: occurring every five years."
      ],
      "synonyms": [
        {
          "extra": "occurring every five years",
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "quinquennial"
        }
      ],
      "tags": [
        "not-comparable",
        "rare"
      ]
    }
  ],
  "word": "pentennial"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "grc",
        "3": "πέντε",
        "4": "",
        "5": "five"
      },
      "expansion": "Ancient Greek πέντε (pénte, “five”)",
      "name": "uder"
    },
    {
      "args": {
        "1": "en",
        "2": "la",
        "3": "annus",
        "4": "",
        "5": "year"
      },
      "expansion": "Latin annus (“year”)",
      "name": "uder"
    },
    {
      "args": {
        "1": "en",
        "2": "",
        "3": "ial"
      },
      "expansion": "+ -ial",
      "name": "suffix"
    }
  ],
  "etymology_text": "From Ancient Greek πέντε (pénte, “five”) + Latin annus (“year”) + -ial.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "pentennial (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English adjectives",
        "English entries with incorrect language header",
        "English entries with topic categories using raw markup",
        "English lemmas",
        "English terms derived from Ancient Greek",
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        "English terms with rare senses",
        "English terms with usage examples",
        "English uncomparable adjectives",
        "English undefined derivations",
        "en:Five"
      ],
      "examples": [
        {
          "text": "The family had plans to attend the pentennial reunion.",
          "type": "example"
        }
      ],
      "glosses": [
        "Synonym of quinquennial: occurring every five years."
      ],
      "links": [
        [
          "quinquennial",
          "quinquennial#English"
        ],
        [
          "occur",
          "occur"
        ],
        [
          "every",
          "every"
        ],
        [
          "five",
          "five"
        ],
        [
          "year",
          "year"
        ]
      ],
      "raw_glosses": [
        "(rare) Synonym of quinquennial: occurring every five years."
      ],
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        {
          "extra": "occurring every five years",
          "tags": [
            "synonym",
            "synonym-of"
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          "word": "quinquennial"
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      "tags": [
        "not-comparable",
        "rare"
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    }
  ],
  "word": "pentennial"
}