"sigma" meaning in Spanish

{
  "forms": [
    {
      "form": "sigmas",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "f"
      },
      "expansion": "sigma f (plural sigmas)",
      "name": "es-noun"
    }
  ],
  "hyphenation": [
    "sig‧ma"
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Spanish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "es",
          "name": "Greek letter names",
          "orig": "es:Greek 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": [
        "sigma; the Greek letter Σ, σ"
      ],
      "id": "en-sigma-es-noun-r9vwu67A",
      "links": [
        [
          "sigma",
          "sigma#English"
        ],
        [
          "Σ",
          "Σ"
        ],
        [
          "σ",
          "σ"
        ]
      ],
      "tags": [
        "feminine"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈsiɡma/"
    },
    {
      "ipa": "[ˈsiɣ̞.ma]"
    },
    {
      "rhymes": "-iɡma"
    }
  ],
  "word": "sigma"
}

{
  "forms": [
    {
      "form": "sigmas",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "f"
      },
      "expansion": "sigma f (plural sigmas)",
      "name": "es-noun"
    }
  ],
  "hyphenation": [
    "sig‧ma"
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Rhymes:Spanish/iɡma",
        "Rhymes:Spanish/iɡma/2 syllables",
        "Spanish 2-syllable words",
        "Spanish countable nouns",
        "Spanish entries with incorrect language header",
        "Spanish feminine nouns",
        "Spanish lemmas",
        "Spanish nouns",
        "Spanish terms with IPA pronunciation",
        "es:Greek letter names"
      ],
      "glosses": [
        "sigma; the Greek letter Σ, σ"
      ],
      "links": [
        [
          "sigma",
          "sigma#English"
        ],
        [
          "Σ",
          "Σ"
        ],
        [
          "σ",
          "σ"
        ]
      ],
      "tags": [
        "feminine"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈsiɡma/"
    },
    {
      "ipa": "[ˈsiɣ̞.ma]"
    },
    {
      "rhymes": "-iɡma"
    }
  ],
  "word": "sigma"
}