"pond scum" meaning in English

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      "expansion": "pond scum (uncountable)",
      "name": "en-noun"
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
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      "categories": [
        {
          "_dis": "93 7",
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      ],
      "glosses": [
        "Algae, especially when growing on the surface of a pond."
      ],
      "id": "en-pond_scum-en-noun--Ipc-atr",
      "links": [
        [
          "Algae",
          "algae"
        ],
        [
          "pond",
          "pond"
        ]
      ],
      "tags": [
        "uncountable"
      ]
    },
    {
      "categories": [
        {
          "_dis": "2 98",
          "kind": "topical",
          "langcode": "en",
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            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w+disamb"
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      ],
      "glosses": [
        "Worthless, insignificant person or people."
      ],
      "id": "en-pond_scum-en-noun-aRT-~0-A",
      "raw_glosses": [
        "(figuratively) Worthless, insignificant person or people."
      ],
      "synonyms": [
        {
          "word": "pondlife"
        }
      ],
      "tags": [
        "figuratively",
        "uncountable"
      ]
    }
  ],
  "word": "pond scum"
}

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      "expansion": "pond scum (uncountable)",
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "glosses": [
        "Algae, especially when growing on the surface of a pond."
      ],
      "links": [
        [
          "Algae",
          "algae"
        ],
        [
          "pond",
          "pond"
        ]
      ],
      "tags": [
        "uncountable"
      ]
    },
    {
      "glosses": [
        "Worthless, insignificant person or people."
      ],
      "raw_glosses": [
        "(figuratively) Worthless, insignificant person or people."
      ],
      "synonyms": [
        {
          "word": "pondlife"
        }
      ],
      "tags": [
        "figuratively",
        "uncountable"
      ]
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  ],
  "word": "pond scum"
}