"reflecting circle" meaning in English

{
  "forms": [
    {
      "form": "reflecting circles",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "reflecting circle (plural reflecting circles)",
      "name": "en-noun"
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
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      "glosses": [
        "An astronomical instrument for measuring angles, like the sextant or Hadley's quadrant, by the reflection of light from two plane mirrors which it carries, and differing from the sextant chiefly in having an entire circle."
      ],
      "id": "en-reflecting_circle-en-noun-aBPvbXmi",
      "links": [
        [
          "sextant",
          "sextant"
        ],
        [
          "Hadley's quadrant",
          "Hadley's quadrant"
        ]
      ],
      "translations": [
        {
          "code": "fr",
          "lang": "French",
          "sense": "Translations",
          "tags": [
            "masculine"
          ],
          "word": "cercle de réflexion"
        }
      ]
    }
  ],
  "word": "reflecting circle"
}

{
  "forms": [
    {
      "form": "reflecting circles",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "reflecting circle (plural reflecting circles)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
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      ],
      "glosses": [
        "An astronomical instrument for measuring angles, like the sextant or Hadley's quadrant, by the reflection of light from two plane mirrors which it carries, and differing from the sextant chiefly in having an entire circle."
      ],
      "links": [
        [
          "sextant",
          "sextant"
        ],
        [
          "Hadley's quadrant",
          "Hadley's quadrant"
        ]
      ]
    }
  ],
  "translations": [
    {
      "code": "fr",
      "lang": "French",
      "sense": "Translations",
      "tags": [
        "masculine"
      ],
      "word": "cercle de réflexion"
    }
  ],
  "word": "reflecting circle"
}