"banana money" meaning in English

{
  "etymology_text": "From the prominent illustration of a banana tree on some series of the notes.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "banana money (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": "topical",
          "langcode": "en",
          "name": "Historical currencies",
          "orig": "en:Historical currencies",
          "parents": [
            "Currencies",
            "Currency",
            "Money",
            "Business",
            "Economics",
            "Society",
            "Social sciences",
            "All topics",
            "Sciences",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "World War II Japanese invasion money."
      ],
      "id": "en-banana_money-en-noun-z593iOkV",
      "links": [
        [
          "invasion money",
          "invasion money"
        ]
      ],
      "raw_glosses": [
        "(informal) World War II Japanese invasion money."
      ],
      "tags": [
        "informal",
        "uncountable"
      ]
    }
  ],
  "word": "banana money"
}

{
  "etymology_text": "From the prominent illustration of a banana tree on some series of the notes.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "banana money (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English informal terms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English uncountable nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Historical currencies"
      ],
      "glosses": [
        "World War II Japanese invasion money."
      ],
      "links": [
        [
          "invasion money",
          "invasion money"
        ]
      ],
      "raw_glosses": [
        "(informal) World War II Japanese invasion money."
      ],
      "tags": [
        "informal",
        "uncountable"
      ]
    }
  ],
  "word": "banana money"
}