"so and so" meaning in English

{
  "forms": [
    {
      "form": "so and sos",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "so and so (plural so and sos)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "so-and-so"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with language name categories using raw markup",
          "parents": [
            "Entries with language name categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English reduplicated coordinated pairs",
          "parents": [
            "Reduplicated coordinated pairs",
            "Coordinated pairs",
            "Reduplications",
            "Terms by etymology"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Alternative spelling of so-and-so"
      ],
      "id": "en-so_and_so-en-noun-IKYTvBRK",
      "links": [
        [
          "so-and-so",
          "so-and-so#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "so and so"
}

{
  "forms": [
    {
      "form": "so and sos",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "so and so (plural so and sos)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "so-and-so"
        }
      ],
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English entries with language name categories using raw markup",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English reduplicated coordinated pairs",
        "English terms with non-redundant non-automated sortkeys"
      ],
      "glosses": [
        "Alternative spelling of so-and-so"
      ],
      "links": [
        [
          "so-and-so",
          "so-and-so#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "so and so"
}