"youth-on-age" meaning in English

{
  "etymology_text": "From the way young plantlets sprout from the middle of older leaves.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "youth-on-age (uncountable)",
      "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": "lifeform",
          "langcode": "en",
          "name": "Saxifragales order plants",
          "orig": "en:Saxifragales order plants",
          "parents": [
            "Plants",
            "Shrubs",
            "Trees",
            "Lifeforms",
            "All topics",
            "Life",
            "Fundamental",
            "Nature"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1972, Hazel Heckman, Island Year, page 132:",
          "text": "Sometimes flowers of youth-on-age are white streaked with green instead of greenish streaked with purple.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A perennial plant native to North America and widely planted as an ornamental: Tolmiea menziesii"
      ],
      "id": "en-youth-on-age-en-noun-~Ak9sWmP",
      "links": [
        [
          "perennial",
          "perennial"
        ]
      ],
      "synonyms": [
        {
          "sense": "Tolmiea menziesii",
          "word": "hedge nettle"
        },
        {
          "sense": "Tolmiea menziesii",
          "word": "piggyback plant"
        },
        {
          "sense": "Tolmiea menziesii",
          "word": "thousand mothers"
        }
      ],
      "tags": [
        "uncountable"
      ]
    }
  ],
  "word": "youth-on-age"
}

{
  "etymology_text": "From the way young plantlets sprout from the middle of older leaves.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "youth-on-age (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "English uncountable nouns",
        "Entries using missing taxonomic name (species)",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Saxifragales order plants"
      ],
      "examples": [
        {
          "ref": "1972, Hazel Heckman, Island Year, page 132:",
          "text": "Sometimes flowers of youth-on-age are white streaked with green instead of greenish streaked with purple.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A perennial plant native to North America and widely planted as an ornamental: Tolmiea menziesii"
      ],
      "links": [
        [
          "perennial",
          "perennial"
        ]
      ],
      "tags": [
        "uncountable"
      ]
    }
  ],
  "synonyms": [
    {
      "sense": "Tolmiea menziesii",
      "word": "hedge nettle"
    },
    {
      "sense": "Tolmiea menziesii",
      "word": "piggyback plant"
    },
    {
      "sense": "Tolmiea menziesii",
      "word": "thousand mothers"
    }
  ],
  "word": "youth-on-age"
}