"s-" meaning in Lushootseed

{
  "head_templates": [
    {
      "args": {
        "1": "lut",
        "2": "prefix"
      },
      "expansion": "s-",
      "name": "head"
    }
  ],
  "lang": "Lushootseed",
  "lang_code": "lut",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Lushootseed entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 17 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "s- + ʔəɬəd (“eat”) → sʔəɬəd (“food”)",
          "type": "example"
        }
      ],
      "glosses": [
        "Added to a verb to form a noun."
      ],
      "id": "en-s--lut-prefix-a-fzU8VU",
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "s-"
}

{
  "head_templates": [
    {
      "args": {
        "1": "lut",
        "2": "prefix"
      },
      "expansion": "s-",
      "name": "head"
    }
  ],
  "lang": "Lushootseed",
  "lang_code": "lut",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        "Lushootseed entries with incorrect language header",
        "Lushootseed lemmas",
        "Lushootseed prefixes",
        "Pages with 17 entries",
        "Pages with entries"
      ],
      "examples": [
        {
          "text": "s- + ʔəɬəd (“eat”) → sʔəɬəd (“food”)",
          "type": "example"
        }
      ],
      "glosses": [
        "Added to a verb to form a noun."
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "s-"
}