"sweet fifteen" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "sweet",
        "3": "fifteen"
      },
      "expansion": "sweet + fifteen",
      "name": "compound"
    },
    {
      "args": {
        "1": "en",
        "2": "sweet sixteen"
      },
      "expansion": "sweet sixteen",
      "name": "m"
    },
    {
      "args": {
        "1": "es",
        "2": "quinceaños"
      },
      "expansion": "quinceaños",
      "name": "m"
    },
    {
      "args": {
        "1": "es",
        "2": "quinceañera"
      },
      "expansion": "quinceañera",
      "name": "m"
    }
  ],
  "etymology_text": "From sweet + fifteen. Coined in analogy to sweet sixteen; Americanization of the Mexican concept of quinceaños or quinceañera.",
  "forms": [
    {
      "form": "sweet fifteens",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "sweet fifteen (plural sweet fifteens)",
      "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"
        }
      ],
      "glosses": [
        "Synonym of quinceanera"
      ],
      "id": "en-sweet_fifteen-en-noun-3iE3DLSJ",
      "links": [
        [
          "quinceanera",
          "quinceanera#English"
        ]
      ],
      "related": [
        {
          "word": "sweet thirteen"
        },
        {
          "word": "sweet sixteen"
        },
        {
          "word": "sweet seventeen"
        },
        {
          "word": "bat mitzvah"
        }
      ],
      "synonyms": [
        {
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "quinceanera"
        },
        {
          "word": "sweet 15"
        }
      ]
    }
  ],
  "word": "sweet fifteen"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "sweet",
        "3": "fifteen"
      },
      "expansion": "sweet + fifteen",
      "name": "compound"
    },
    {
      "args": {
        "1": "en",
        "2": "sweet sixteen"
      },
      "expansion": "sweet sixteen",
      "name": "m"
    },
    {
      "args": {
        "1": "es",
        "2": "quinceaños"
      },
      "expansion": "quinceaños",
      "name": "m"
    },
    {
      "args": {
        "1": "es",
        "2": "quinceañera"
      },
      "expansion": "quinceañera",
      "name": "m"
    }
  ],
  "etymology_text": "From sweet + fifteen. Coined in analogy to sweet sixteen; Americanization of the Mexican concept of quinceaños or quinceañera.",
  "forms": [
    {
      "form": "sweet fifteens",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "sweet fifteen (plural sweet fifteens)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "sweet thirteen"
    },
    {
      "word": "sweet sixteen"
    },
    {
      "word": "sweet seventeen"
    },
    {
      "word": "bat mitzvah"
    }
  ],
  "senses": [
    {
      "categories": [
        "English compound terms",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns"
      ],
      "glosses": [
        "Synonym of quinceanera"
      ],
      "links": [
        [
          "quinceanera",
          "quinceanera#English"
        ]
      ],
      "synonyms": [
        {
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "quinceanera"
        }
      ]
    }
  ],
  "synonyms": [
    {
      "word": "sweet 15"
    }
  ],
  "word": "sweet fifteen"
}