"but if" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "conjunction"
      },
      "expansion": "but if",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "conj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1485, Sir Thomas Malory, Le Morte Darthur, Book VIII",
          "text": "And therewithall he swange oute a swerde and seyde, ‘But yf thou telle me all who hath ben here, now shalt thou dey!’",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Unless."
      ],
      "id": "en-but_if-en-conj-QO9ql4GM",
      "links": [
        [
          "Unless",
          "unless"
        ]
      ],
      "raw_glosses": [
        "(obsolete) Unless."
      ],
      "tags": [
        "obsolete"
      ]
    }
  ],
  "word": "but if"
}

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "conjunction"
      },
      "expansion": "but if",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "conj",
  "senses": [
    {
      "categories": [
        "English conjunctions",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English terms with obsolete senses",
        "English terms with quotations",
        "Quotation templates to be cleaned"
      ],
      "examples": [
        {
          "ref": "1485, Sir Thomas Malory, Le Morte Darthur, Book VIII",
          "text": "And therewithall he swange oute a swerde and seyde, ‘But yf thou telle me all who hath ben here, now shalt thou dey!’",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Unless."
      ],
      "links": [
        [
          "Unless",
          "unless"
        ]
      ],
      "raw_glosses": [
        "(obsolete) Unless."
      ],
      "tags": [
        "obsolete"
      ]
    }
  ],
  "word": "but if"
}