"croce di Einstein" meaning in Italien

{
  "categories": [
    {
      "kind": "other",
      "name": "Locutions nominales en italien",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Italien",
      "orig": "italien",
      "parents": [],
      "source": "w"
    }
  ],
  "forms": [
    {
      "form": "croci di Einstein",
      "tags": [
        "plural"
      ]
    }
  ],
  "lang": "Italien",
  "lang_code": "it",
  "pos": "noun",
  "pos_title": "Locution nominale",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Lexique en italien de l’astronomie",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Wiktionnaire:Exemples manquants en italien",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Croix d’Einstein."
      ],
      "id": "fr-croce_di_Einstein-it-noun-dSMkXq1~",
      "topics": [
        "astronomy"
      ]
    }
  ],
  "tags": [
    "feminine"
  ],
  "word": "croce di Einstein"
}

{
  "categories": [
    "Locutions nominales en italien",
    "italien"
  ],
  "forms": [
    {
      "form": "croci di Einstein",
      "tags": [
        "plural"
      ]
    }
  ],
  "lang": "Italien",
  "lang_code": "it",
  "pos": "noun",
  "pos_title": "Locution nominale",
  "senses": [
    {
      "categories": [
        "Lexique en italien de l’astronomie",
        "Wiktionnaire:Exemples manquants en italien"
      ],
      "glosses": [
        "Croix d’Einstein."
      ],
      "topics": [
        "astronomy"
      ]
    }
  ],
  "tags": [
    "feminine"
  ],
  "word": "croce di Einstein"
}