"Pℓ" meaning in Universeel taalgebruik

{
  "categories": [
    {
      "kind": "other",
      "name": "Symbool",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Woorden in het universeel taalgebruik",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_texts": [
    "Samenstelling van “ℓ” (liter) met het voorvoegsel “P” (peta-)"
  ],
  "forms": [
    {
      "form": "PL, Pl"
    }
  ],
  "lang": "Universeel taalgebruik",
  "lang_code": "unknown",
  "pos": "symbol",
  "pos_title": "Symbool",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Eenheid_in_het_universeel taalgebruik",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Wiskunde_in_het_universeel taalgebruik",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "het symbool voor petaliter, gelijk aan 1.000.000.000.000.000 liter"
      ],
      "id": "nl-Pℓ-unknown-symbol-oRtfVt2o",
      "topics": [
        "mathematics",
        "units-of-measure"
      ]
    }
  ],
  "word": "Pℓ"
}

{
  "categories": [
    "Symbool",
    "Woorden in het universeel taalgebruik"
  ],
  "etymology_texts": [
    "Samenstelling van “ℓ” (liter) met het voorvoegsel “P” (peta-)"
  ],
  "forms": [
    {
      "form": "PL, Pl"
    }
  ],
  "lang": "Universeel taalgebruik",
  "lang_code": "unknown",
  "pos": "symbol",
  "pos_title": "Symbool",
  "senses": [
    {
      "categories": [
        "Eenheid_in_het_universeel taalgebruik",
        "Wiskunde_in_het_universeel taalgebruik"
      ],
      "glosses": [
        "het symbool voor petaliter, gelijk aan 1.000.000.000.000.000 liter"
      ],
      "topics": [
        "mathematics",
        "units-of-measure"
      ]
    }
  ],
  "word": "Pℓ"
}