"initialism" meaning in English

{
  "categories": [
    {
      "kind": "other",
      "name": "Terms suffixed with -ism",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "initial",
        "2": "ism"
      },
      "expansion": "initial + -ism",
      "name": "ety-suffix"
    }
  ],
  "etymology_text": "initial + -ism",
  "forms": [
    {
      "form": "initialism",
      "tags": [
        "singular"
      ]
    },
    {
      "form": "initialisms",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "expansion": "[POS TABLE]",
      "name": "noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Linguistics",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "BBC is an initialism for British Broadcasting Corporation."
        }
      ],
      "glosses": [
        "Initialise is a term formed by using the initial letters of several words or parts of words."
      ],
      "id": "simple-initialism-en-noun-CW5MkM43",
      "raw_tags": [
        "linguistics"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ɪˈnɪʃəlɪzəm/"
    },
    {
      "audio": "LL-Q1860 (eng)-Vealhurl-initialism.wav",
      "raw_tags": [
        "Audio"
      ],
      "tags": [
        "UK"
      ]
    }
  ],
  "word": "initialism"
}

{
  "categories": [
    "Terms suffixed with -ism"
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "initial",
        "2": "ism"
      },
      "expansion": "initial + -ism",
      "name": "ety-suffix"
    }
  ],
  "etymology_text": "initial + -ism",
  "forms": [
    {
      "form": "initialism",
      "tags": [
        "singular"
      ]
    },
    {
      "form": "initialisms",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "expansion": "[POS TABLE]",
      "name": "noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Linguistics"
      ],
      "examples": [
        {
          "text": "BBC is an initialism for British Broadcasting Corporation."
        }
      ],
      "glosses": [
        "Initialise is a term formed by using the initial letters of several words or parts of words."
      ],
      "raw_tags": [
        "linguistics"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ɪˈnɪʃəlɪzəm/"
    },
    {
      "audio": "LL-Q1860 (eng)-Vealhurl-initialism.wav",
      "raw_tags": [
        "Audio"
      ],
      "tags": [
        "UK"
      ]
    }
  ],
  "word": "initialism"
}