"concrete cow" meaning in Anglais

{
  "categories": [
    {
      "kind": "other",
      "name": "Locutions nominales en anglais",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Anglais",
      "orig": "anglais",
      "parents": [],
      "source": "w"
    }
  ],
  "forms": [
    {
      "form": "concrete cows",
      "tags": [
        "plural"
      ]
    }
  ],
  "lang": "Anglais",
  "lang_code": "en",
  "pos": "noun",
  "pos_title": "Locution nominale",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Exemples en anglais",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Exemples en anglais à traduire",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              101,
              113
            ]
          ],
          "ref": "« Climate responsibility », Severn Trent Water",
          "text": "Crop materials are fed into large airtight tanks called anaerobic digesters. These are known as the “concrete cow” as the process is similar to what goes on in a cow’s stomach."
        }
      ],
      "glosses": [
        "Bâtiment dans lequel des résidus de récolte ou alimentaires sont mis à fermenter à l'abri de l'air pour produire des biogaz."
      ],
      "id": "fr-concrete_cow-en-noun-n0aSiqke"
    }
  ],
  "synonyms": [
    {
      "word": "anaerobic digester"
    }
  ],
  "word": "concrete cow"
}

{
  "categories": [
    "Locutions nominales en anglais",
    "anglais"
  ],
  "forms": [
    {
      "form": "concrete cows",
      "tags": [
        "plural"
      ]
    }
  ],
  "lang": "Anglais",
  "lang_code": "en",
  "pos": "noun",
  "pos_title": "Locution nominale",
  "senses": [
    {
      "categories": [
        "Exemples en anglais",
        "Exemples en anglais à traduire"
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              101,
              113
            ]
          ],
          "ref": "« Climate responsibility », Severn Trent Water",
          "text": "Crop materials are fed into large airtight tanks called anaerobic digesters. These are known as the “concrete cow” as the process is similar to what goes on in a cow’s stomach."
        }
      ],
      "glosses": [
        "Bâtiment dans lequel des résidus de récolte ou alimentaires sont mis à fermenter à l'abri de l'air pour produire des biogaz."
      ]
    }
  ],
  "synonyms": [
    {
      "word": "anaerobic digester"
    }
  ],
  "word": "concrete cow"
}