"Irish acre" meaning in English

{
  "etymology_text": "It was historically used in Ireland.",
  "forms": [
    {
      "form": "Irish acres",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Irish acre (plural Irish acres)",
      "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"
        }
      ],
      "glosses": [
        "A unit of area equal to 7840 square yards (approximately 0.66 hectares or 1.62 statute acres)."
      ],
      "id": "en-Irish_acre-en-noun-pWUtDal6",
      "links": [
        [
          "unit",
          "unit"
        ],
        [
          "area",
          "area"
        ],
        [
          "hectare",
          "hectare"
        ]
      ],
      "raw_glosses": [
        "(historical) A unit of area equal to 7840 square yards (approximately 0.66 hectares or 1.62 statute acres)."
      ],
      "synonyms": [
        {
          "word": "plantation acre"
        }
      ],
      "tags": [
        "historical"
      ]
    }
  ],
  "word": "Irish acre"
}

{
  "etymology_text": "It was historically used in Ireland.",
  "forms": [
    {
      "form": "Irish acres",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Irish acre (plural Irish acres)",
      "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 historical senses"
      ],
      "glosses": [
        "A unit of area equal to 7840 square yards (approximately 0.66 hectares or 1.62 statute acres)."
      ],
      "links": [
        [
          "unit",
          "unit"
        ],
        [
          "area",
          "area"
        ],
        [
          "hectare",
          "hectare"
        ]
      ],
      "raw_glosses": [
        "(historical) A unit of area equal to 7840 square yards (approximately 0.66 hectares or 1.62 statute acres)."
      ],
      "synonyms": [
        {
          "word": "plantation acre"
        }
      ],
      "tags": [
        "historical"
      ]
    }
  ],
  "word": "Irish acre"
}