"Celticism" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "Celtic",
        "3": "ism"
      },
      "expansion": "Celtic + -ism",
      "name": "suffix"
    }
  ],
  "etymology_text": "Celtic + -ism",
  "forms": [
    {
      "form": "Celticisms",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Celticism (plural Celticisms)",
      "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": "English terms suffixed with -ism",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1782, Thomas Warton, The History and Antiquities of Kiddington",
          "text": "The latter [Rollright Stones], which has every signature of Celticism, I conceive to be coeval and perhaps of a class with Stone - henge .",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A Celtic custom or idiom."
      ],
      "id": "en-Celticism-en-noun-19jV7T0r",
      "links": [
        [
          "Celtic",
          "Celtic"
        ],
        [
          "custom",
          "custom"
        ],
        [
          "idiom",
          "idiom"
        ]
      ]
    }
  ],
  "word": "Celticism"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "Celtic",
        "3": "ism"
      },
      "expansion": "Celtic + -ism",
      "name": "suffix"
    }
  ],
  "etymology_text": "Celtic + -ism",
  "forms": [
    {
      "form": "Celticisms",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Celticism (plural Celticisms)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English terms suffixed with -ism",
        "English terms with quotations",
        "Quotation templates to be cleaned"
      ],
      "examples": [
        {
          "ref": "1782, Thomas Warton, The History and Antiquities of Kiddington",
          "text": "The latter [Rollright Stones], which has every signature of Celticism, I conceive to be coeval and perhaps of a class with Stone - henge .",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A Celtic custom or idiom."
      ],
      "links": [
        [
          "Celtic",
          "Celtic"
        ],
        [
          "custom",
          "custom"
        ],
        [
          "idiom",
          "idiom"
        ]
      ]
    }
  ],
  "word": "Celticism"
}