"fight a losing battle" meaning in English

{
  "forms": [
    {
      "form": "fights a losing battle",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "fighting a losing battle",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "fought a losing battle",
      "tags": [
        "participle",
        "past"
      ]
    },
    {
      "form": "fought a losing battle",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "fight<,,fought> a losing battle"
      },
      "expansion": "fight a losing battle (third-person singular simple present fights a losing battle, present participle fighting a losing battle, simple past and past participle fought a losing battle)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        {
          "_dis": "54 46",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "To continue to wage war when it is clear that one is not going to win."
      ],
      "id": "en-fight_a_losing_battle-en-verb-loRSiYLe"
    },
    {
      "categories": [
        {
          "_dis": "54 46",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "examples": [
        {
          "ref": "1984, Lucy Gore, Diary Of A Working Mum, page 18",
          "text": "The bus was oppressively warm and the air-conditioning was fighting a losing battle with the heat.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "To try to do something so difficult that it will probably end in failure."
      ],
      "id": "en-fight_a_losing_battle-en-verb-whNd3bgj",
      "links": [
        [
          "difficult",
          "difficult"
        ],
        [
          "failure",
          "failure"
        ]
      ],
      "raw_glosses": [
        "(idiomatic) To try to do something so difficult that it will probably end in failure."
      ],
      "synonyms": [
        {
          "_dis1": "37 63",
          "word": "fight a rearguard action"
        }
      ],
      "tags": [
        "idiomatic"
      ]
    }
  ],
  "sounds": [
    {
      "audio": "en-au-fight a losing battle.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/d/d2/En-au-fight_a_losing_battle.ogg/En-au-fight_a_losing_battle.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/d/d2/En-au-fight_a_losing_battle.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "word": "fight a losing battle"
}

{
  "categories": [
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English terms with audio links",
    "English verbs"
  ],
  "forms": [
    {
      "form": "fights a losing battle",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "fighting a losing battle",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "fought a losing battle",
      "tags": [
        "participle",
        "past"
      ]
    },
    {
      "form": "fought a losing battle",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "fight<,,fought> a losing battle"
      },
      "expansion": "fight a losing battle (third-person singular simple present fights a losing battle, present participle fighting a losing battle, simple past and past participle fought a losing battle)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "glosses": [
        "To continue to wage war when it is clear that one is not going to win."
      ]
    },
    {
      "categories": [
        "English idioms",
        "English terms with quotations",
        "Quotation templates to be cleaned"
      ],
      "examples": [
        {
          "ref": "1984, Lucy Gore, Diary Of A Working Mum, page 18",
          "text": "The bus was oppressively warm and the air-conditioning was fighting a losing battle with the heat.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "To try to do something so difficult that it will probably end in failure."
      ],
      "links": [
        [
          "difficult",
          "difficult"
        ],
        [
          "failure",
          "failure"
        ]
      ],
      "raw_glosses": [
        "(idiomatic) To try to do something so difficult that it will probably end in failure."
      ],
      "tags": [
        "idiomatic"
      ]
    }
  ],
  "sounds": [
    {
      "audio": "en-au-fight a losing battle.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/d/d2/En-au-fight_a_losing_battle.ogg/En-au-fight_a_losing_battle.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/d/d2/En-au-fight_a_losing_battle.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "synonyms": [
    {
      "word": "fight a rearguard action"
    }
  ],
  "word": "fight a losing battle"
}