"terminal s" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "?"
      },
      "expansion": "terminal s",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with topic categories using raw markup",
          "parents": [
            "Entries with topic categories using raw markup",
            "Entry maintenance"
          ],
          "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"
        },
        {
          "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": [
        "Synonym of short s"
      ],
      "id": "en-terminal_s-en-noun-xMcBn2Ga",
      "links": [
        [
          "short s",
          "short s#English"
        ]
      ],
      "synonyms": [
        {
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "short s"
        }
      ]
    }
  ],
  "word": "terminal s"
}

{
  "head_templates": [
    {
      "args": {
        "1": "?"
      },
      "expansion": "terminal s",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with topic categories using raw markup",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English nouns with unknown or uncertain plurals",
        "English terms with non-redundant non-automated sortkeys",
        "en:Latin letter names"
      ],
      "glosses": [
        "Synonym of short s"
      ],
      "links": [
        [
          "short s",
          "short s#English"
        ]
      ],
      "synonyms": [
        {
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "short s"
        }
      ]
    }
  ],
  "word": "terminal s"
}