"unforced error" meaning in English

{
  "forms": [
    {
      "form": "unforced errors",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "unforced error (plural unforced errors)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Sports",
          "orig": "en:Sports",
          "parents": [
            "Human activity",
            "Human behaviour",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Tennis",
          "orig": "en:Tennis",
          "parents": [
            "Ball games",
            "Racquet sports",
            "Sports",
            "Human activity",
            "Human behaviour",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2012 June 28, Jamie Jackson, “Wimbledon 2012: Lukas Rosol shocked by miracle win over Rafael Nadal”, in the Guardian:",
          "text": "This meant Nadal needed to hold serve to force his opponent to earn the win. An unforced error took Rosol to 30-15 and two points away from glory, but a net cord in Nadal's favour and the men were level in the game.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A basic error committed in a tactical game, where errors are usually forced by the game strategy."
      ],
      "id": "en-unforced_error-en-noun-GRoFoX7T",
      "links": [
        [
          "sports",
          "sports"
        ],
        [
          "tennis",
          "tennis"
        ],
        [
          "tactical",
          "tactical"
        ],
        [
          "strategy",
          "strategy"
        ]
      ],
      "raw_glosses": [
        "(sports, chiefly tennis) A basic error committed in a tactical game, where errors are usually forced by the game strategy."
      ],
      "synonyms": [
        {
          "word": "blunder"
        },
        {
          "word": "clanger"
        }
      ],
      "topics": [
        "hobbies",
        "lifestyle",
        "sports",
        "tennis"
      ]
    }
  ],
  "word": "unforced error"
}

{
  "forms": [
    {
      "form": "unforced errors",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "unforced error (plural unforced errors)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Sports",
        "en:Tennis"
      ],
      "examples": [
        {
          "ref": "2012 June 28, Jamie Jackson, “Wimbledon 2012: Lukas Rosol shocked by miracle win over Rafael Nadal”, in the Guardian:",
          "text": "This meant Nadal needed to hold serve to force his opponent to earn the win. An unforced error took Rosol to 30-15 and two points away from glory, but a net cord in Nadal's favour and the men were level in the game.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A basic error committed in a tactical game, where errors are usually forced by the game strategy."
      ],
      "links": [
        [
          "sports",
          "sports"
        ],
        [
          "tennis",
          "tennis"
        ],
        [
          "tactical",
          "tactical"
        ],
        [
          "strategy",
          "strategy"
        ]
      ],
      "raw_glosses": [
        "(sports, chiefly tennis) A basic error committed in a tactical game, where errors are usually forced by the game strategy."
      ],
      "topics": [
        "hobbies",
        "lifestyle",
        "sports",
        "tennis"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "blunder"
    },
    {
      "word": "clanger"
    }
  ],
  "word": "unforced error"
}