"without batting an eye" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "without batting an eye (not comparable)",
      "name": "en-adv"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2015, Allison Hobbs, Karen E. Quinones Miller, Hittin' It Out the Park, page 111",
          "text": "Now here she was dropping almost $5,000 on a single outfit without batting an eye.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Showing no emotional reaction."
      ],
      "id": "en-without_batting_an_eye-en-adv-3kKWvsMM",
      "links": [
        [
          "emotional",
          "emotional"
        ],
        [
          "reaction",
          "reaction"
        ]
      ],
      "synonyms": [
        {
          "word": "without batting an eyelid"
        },
        {
          "word": "without batting an eyelash"
        },
        {
          "word": "without blinking an eye"
        },
        {
          "word": "without blinking an eyelid"
        },
        {
          "word": "without blinking an eyelash"
        }
      ],
      "tags": [
        "not-comparable"
      ]
    }
  ],
  "word": "without batting an eye"
}

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "without batting an eye (not comparable)",
      "name": "en-adv"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        "English adverbs",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English terms with quotations",
        "English uncomparable adverbs"
      ],
      "examples": [
        {
          "ref": "2015, Allison Hobbs, Karen E. Quinones Miller, Hittin' It Out the Park, page 111",
          "text": "Now here she was dropping almost $5,000 on a single outfit without batting an eye.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Showing no emotional reaction."
      ],
      "links": [
        [
          "emotional",
          "emotional"
        ],
        [
          "reaction",
          "reaction"
        ]
      ],
      "tags": [
        "not-comparable"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "without batting an eyelid"
    },
    {
      "word": "without batting an eyelash"
    },
    {
      "word": "without blinking an eye"
    },
    {
      "word": "without blinking an eyelid"
    },
    {
      "word": "without blinking an eyelash"
    }
  ],
  "word": "without batting an eye"
}