"of a certain age" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "fr",
        "3": "d'un certain âge",
        "nocap": "1"
      },
      "expansion": "calque of French d’un certain âge",
      "name": "cal"
    }
  ],
  "etymology_text": "Perhaps a calque of French d’un certain âge.",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "prepositional phrase",
        "head": ""
      },
      "expansion": "of a certain age",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "of a certain age",
      "name": "en-PP"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "prep_phrase",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English euphemisms",
          "parents": [],
          "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": "Age",
          "orig": "en:Age",
          "parents": [
            "Human",
            "Time",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "Near-synonyms: (indeterminate) getting on in years, on in years, long in the tooth; (past middle age) older, senior, elderly, geriatric; see also Thesaurus:elderly"
        },
        {
          "text": "a lady of a certain age",
          "type": "example"
        },
        {
          "text": "Now that I'm of a certain age, I need reading glasses to see up close.",
          "type": "example"
        },
        {
          "ref": "1989, Graham Lyle, Albert Hammond (lyrics and music), “I Don't Wanna Lose You”, in Foreign Affair, performed by Tina Turner:",
          "text": "Women of a certain age / They learn to rely and your job is responses / Having played the mating game",
          "type": "quote"
        }
      ],
      "glosses": [
        "Middle-aged or older."
      ],
      "id": "en-of_a_certain_age-en-prep_phrase-SAHv4rCK",
      "links": [
        [
          "Middle-aged",
          "middle-aged"
        ]
      ],
      "raw_glosses": [
        "(euphemistic, chiefly of a person) Middle-aged or older."
      ],
      "raw_tags": [
        "of a person"
      ],
      "related": [
        {
          "word": "time of life"
        }
      ],
      "tags": [
        "euphemistic"
      ]
    }
  ],
  "word": "of a certain age"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "fr",
        "3": "d'un certain âge",
        "nocap": "1"
      },
      "expansion": "calque of French d’un certain âge",
      "name": "cal"
    }
  ],
  "etymology_text": "Perhaps a calque of French d’un certain âge.",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "prepositional phrase",
        "head": ""
      },
      "expansion": "of a certain age",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "of a certain age",
      "name": "en-PP"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "prep_phrase",
  "related": [
    {
      "word": "time of life"
    }
  ],
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English euphemisms",
        "English lemmas",
        "English multiword terms",
        "English prepositional phrases",
        "English terms calqued from French",
        "English terms derived from French",
        "English terms with quotations",
        "English terms with usage examples",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Age"
      ],
      "examples": [
        {
          "text": "Near-synonyms: (indeterminate) getting on in years, on in years, long in the tooth; (past middle age) older, senior, elderly, geriatric; see also Thesaurus:elderly"
        },
        {
          "text": "a lady of a certain age",
          "type": "example"
        },
        {
          "text": "Now that I'm of a certain age, I need reading glasses to see up close.",
          "type": "example"
        },
        {
          "ref": "1989, Graham Lyle, Albert Hammond (lyrics and music), “I Don't Wanna Lose You”, in Foreign Affair, performed by Tina Turner:",
          "text": "Women of a certain age / They learn to rely and your job is responses / Having played the mating game",
          "type": "quote"
        }
      ],
      "glosses": [
        "Middle-aged or older."
      ],
      "links": [
        [
          "Middle-aged",
          "middle-aged"
        ]
      ],
      "raw_glosses": [
        "(euphemistic, chiefly of a person) Middle-aged or older."
      ],
      "raw_tags": [
        "of a person"
      ],
      "tags": [
        "euphemistic"
      ]
    }
  ],
  "word": "of a certain age"
}