"pluralia tantum" meaning in Espagnol

{
  "categories": [
    {
      "kind": "other",
      "name": "Formes de locutions nominales en espagnol",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Genres manquants en espagnol",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Pluriels latins en anglais",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Pluriels latins en espagnol",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Pluriels latins en français",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Espagnol",
      "orig": "espagnol",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Espagnol",
  "lang_code": "es",
  "pos": "noun",
  "pos_title": "Forme de locution nominale",
  "raw_tags": [
    "genre à préciser : {{m}}, {{f}}, {{mf}}, {{n}} ?"
  ],
  "senses": [
    {
      "form_of": [
        {
          "word": "plurale tantum"
        }
      ],
      "glosses": [
        "Pluriel de plurale tantum."
      ],
      "id": "fr-pluralia_tantum-es-noun-EiifAYls"
    }
  ],
  "tags": [
    "form-of"
  ],
  "word": "pluralia tantum"
}

{
  "categories": [
    "Formes de locutions nominales en espagnol",
    "Genres manquants en espagnol",
    "Pluriels latins en anglais",
    "Pluriels latins en espagnol",
    "Pluriels latins en français",
    "espagnol"
  ],
  "lang": "Espagnol",
  "lang_code": "es",
  "pos": "noun",
  "pos_title": "Forme de locution nominale",
  "raw_tags": [
    "genre à préciser : {{m}}, {{f}}, {{mf}}, {{n}} ?"
  ],
  "senses": [
    {
      "form_of": [
        {
          "word": "plurale tantum"
        }
      ],
      "glosses": [
        "Pluriel de plurale tantum."
      ]
    }
  ],
  "tags": [
    "form-of"
  ],
  "word": "pluralia tantum"
}