"double S" meaning in English

{
  "forms": [
    {
      "form": "double S's",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "'s"
      },
      "expansion": "double S (plural double S's)",
      "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": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "German",
          "orig": "en:German",
          "parents": [
            "Languages",
            "Language",
            "Names",
            "Communication",
            "All topics",
            "Proper nouns",
            "Terms by semantic function",
            "Fundamental",
            "Nouns",
            "Lemmas"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Latin letter names",
          "orig": "en:Latin letter names",
          "parents": [
            "Letter names",
            "Letters, symbols, and punctuation",
            "Names",
            "Orthography",
            "All topics",
            "Proper nouns",
            "Terms by semantic function",
            "Writing",
            "Fundamental",
            "Nouns",
            "Human behaviour",
            "Language",
            "Lemmas",
            "Human",
            "Communication"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "The name of the Latin-script letter ẞ/ß."
      ],
      "id": "en-double_S-en-noun-d4pPNnhm",
      "links": [
        [
          "ẞ",
          "ẞ#English"
        ],
        [
          "ß",
          "ß#English"
        ]
      ],
      "synonyms": [
        {
          "word": "eszett"
        },
        {
          "word": "sharp s"
        },
        {
          "word": "double s"
        },
        {
          "word": "double-s"
        }
      ]
    }
  ],
  "word": "double S"
}

{
  "forms": [
    {
      "form": "double S's",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "'s"
      },
      "expansion": "double S (plural double S's)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:German",
        "en:Latin letter names"
      ],
      "glosses": [
        "The name of the Latin-script letter ẞ/ß."
      ],
      "links": [
        [
          "ẞ",
          "ẞ#English"
        ],
        [
          "ß",
          "ß#English"
        ]
      ],
      "synonyms": [
        {
          "word": "eszett"
        },
        {
          "word": "sharp s"
        }
      ]
    }
  ],
  "synonyms": [
    {
      "word": "double s"
    },
    {
      "word": "double-s"
    }
  ],
  "word": "double S"
}