"СПб" meaning in Russian

{
  "forms": [
    {
      "form": "SPb",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "",
        "2": "m-in",
        "3": "-"
      },
      "expansion": "СПб • (SPb) m inan (indeclinable)",
      "name": "ru-noun"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "Sánkt-Peterbúrg",
          "word": "Са́нкт-Петербу́рг"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "Pages with 2 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Russian entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Initialism of Са́нкт-Петербу́рг (Sánkt-Peterbúrg)"
      ],
      "id": "en-СПб-ru-noun-SttJHzWs",
      "links": [
        [
          "Са́нкт-Петербу́рг",
          "Санкт-Петербург#Russian"
        ]
      ],
      "synonyms": [
        {
          "roman": "spb",
          "word": "спб"
        }
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "indeclinable",
        "initialism"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ɛs pɛ ˈbɛ]"
    },
    {
      "ipa": "[ˌsankt pʲɪtʲɪrˈburk]"
    }
  ],
  "word": "СПб"
}

{
  "forms": [
    {
      "form": "SPb",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "",
        "2": "m-in",
        "3": "-"
      },
      "expansion": "СПб • (SPb) m inan (indeclinable)",
      "name": "ru-noun"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "Sánkt-Peterbúrg",
          "word": "Са́нкт-Петербу́рг"
        }
      ],
      "categories": [
        "Pages with 2 entries",
        "Pages with entries",
        "Russian entries with incorrect language header",
        "Russian inanimate nouns",
        "Russian indeclinable nouns",
        "Russian initialisms",
        "Russian lemmas",
        "Russian masculine nouns",
        "Russian nouns",
        "Russian terms with IPA pronunciation",
        "Russian terms with redundant head parameter"
      ],
      "glosses": [
        "Initialism of Са́нкт-Петербу́рг (Sánkt-Peterbúrg)"
      ],
      "links": [
        [
          "Са́нкт-Петербу́рг",
          "Санкт-Петербург#Russian"
        ]
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "indeclinable",
        "initialism"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ɛs pɛ ˈbɛ]"
    },
    {
      "ipa": "[ˌsankt pʲɪtʲɪrˈburk]"
    }
  ],
  "synonyms": [
    {
      "roman": "spb",
      "word": "спб"
    }
  ],
  "word": "СПб"
}