"X-" meaning in Portuguese

{
  "etymology_templates": [
    {
      "args": {
        "1": "pt",
        "2": "X-búrguer"
      },
      "expansion": "Back-formation from X-búrguer",
      "name": "back-formation"
    }
  ],
  "etymology_text": "Back-formation from X-búrguer.",
  "head_templates": [
    {
      "args": {
        "1": "pt",
        "2": "prefix",
        "g": "m"
      },
      "expansion": "X- m",
      "name": "head"
    }
  ],
  "lang": "Portuguese",
  "lang_code": "pt",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Brazilian Portuguese",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Portuguese back-formations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Portuguese entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "pt",
          "name": "Cooking",
          "orig": "pt:Cooking",
          "parents": [
            "Food and drink",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "pt",
          "name": "Sandwiches",
          "orig": "pt:Sandwiches",
          "parents": [
            "Foods",
            "Eating",
            "Food and drink",
            "Human behaviour",
            "All topics",
            "Human",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "X- + salada (“salad”) → X-salada (“burger with salad”)",
          "type": "example"
        },
        {
          "text": "X- + tudo (“everything”) → X-tudo (“burger with everything”)",
          "type": "example"
        }
      ],
      "glosses": [
        "Combined with a relevant filling to form the name of a burger or other fast food item."
      ],
      "id": "en-X--pt-prefix-lJ8u3Ufk",
      "links": [
        [
          "cooking",
          "cooking#Noun"
        ],
        [
          "burger",
          "burger#English"
        ],
        [
          "fast food",
          "fast food#English"
        ]
      ],
      "raw_glosses": [
        "(informal, Brazil, cooking) Combined with a relevant filling to form the name of a burger or other fast food item."
      ],
      "synonyms": [
        {
          "word": "x-"
        },
        {
          "word": "X"
        },
        {
          "word": "xis"
        }
      ],
      "tags": [
        "Brazil",
        "informal",
        "masculine",
        "morpheme"
      ],
      "topics": [
        "cooking",
        "food",
        "lifestyle"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ʃis/",
      "tags": [
        "Brazil"
      ]
    },
    {
      "ipa": "/ʃis/",
      "tags": [
        "Brazil"
      ]
    },
    {
      "ipa": "/ʃiʃ/",
      "tags": [
        "Rio-de-Janeiro"
      ]
    },
    {
      "ipa": "/ʃiʃ/",
      "tags": [
        "Portugal"
      ]
    }
  ],
  "word": "X-"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "pt",
        "2": "X-búrguer"
      },
      "expansion": "Back-formation from X-búrguer",
      "name": "back-formation"
    }
  ],
  "etymology_text": "Back-formation from X-búrguer.",
  "head_templates": [
    {
      "args": {
        "1": "pt",
        "2": "prefix",
        "g": "m"
      },
      "expansion": "X- m",
      "name": "head"
    }
  ],
  "lang": "Portuguese",
  "lang_code": "pt",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        "Brazilian Portuguese",
        "Pages with 1 entry",
        "Pages with entries",
        "Portuguese 1-syllable words",
        "Portuguese back-formations",
        "Portuguese entries with incorrect language header",
        "Portuguese informal terms",
        "Portuguese lemmas",
        "Portuguese prefixes",
        "Portuguese terms with IPA pronunciation",
        "pt:Cooking",
        "pt:Sandwiches"
      ],
      "examples": [
        {
          "text": "X- + salada (“salad”) → X-salada (“burger with salad”)",
          "type": "example"
        },
        {
          "text": "X- + tudo (“everything”) → X-tudo (“burger with everything”)",
          "type": "example"
        }
      ],
      "glosses": [
        "Combined with a relevant filling to form the name of a burger or other fast food item."
      ],
      "links": [
        [
          "cooking",
          "cooking#Noun"
        ],
        [
          "burger",
          "burger#English"
        ],
        [
          "fast food",
          "fast food#English"
        ]
      ],
      "raw_glosses": [
        "(informal, Brazil, cooking) Combined with a relevant filling to form the name of a burger or other fast food item."
      ],
      "tags": [
        "Brazil",
        "informal",
        "masculine",
        "morpheme"
      ],
      "topics": [
        "cooking",
        "food",
        "lifestyle"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ʃis/",
      "tags": [
        "Brazil"
      ]
    },
    {
      "ipa": "/ʃis/",
      "tags": [
        "Brazil"
      ]
    },
    {
      "ipa": "/ʃiʃ/",
      "tags": [
        "Rio-de-Janeiro"
      ]
    },
    {
      "ipa": "/ʃiʃ/",
      "tags": [
        "Portugal"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "x-"
    },
    {
      "word": "X"
    },
    {
      "word": "xis"
    }
  ],
  "word": "X-"
}