"unit matrix" meaning in All languages combined

{
  "forms": [
    {
      "form": "unit matrices",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "unit matrixes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "unit matrices",
        "2": "+"
      },
      "expansion": "unit matrix (plural unit matrices or unit matrixes)",
      "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": "topical",
          "langcode": "en",
          "name": "Linear algebra",
          "orig": "en:Linear algebra",
          "parents": [
            "Algebra",
            "Mathematics",
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "An identity matrix"
      ],
      "id": "en-unit_matrix-en-noun-mOfmT3zM",
      "links": [
        [
          "linear algebra",
          "linear algebra"
        ],
        [
          "identity matrix",
          "identity matrix"
        ]
      ],
      "raw_glosses": [
        "(linear algebra) An identity matrix"
      ],
      "topics": [
        "linear-algebra",
        "mathematics",
        "sciences"
      ]
    }
  ],
  "word": "unit matrix"
}

{
  "forms": [
    {
      "form": "unit matrices",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "unit matrixes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "unit matrices",
        "2": "+"
      },
      "expansion": "unit matrix (plural unit matrices or unit matrixes)",
      "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",
        "en:Linear algebra"
      ],
      "glosses": [
        "An identity matrix"
      ],
      "links": [
        [
          "linear algebra",
          "linear algebra"
        ],
        [
          "identity matrix",
          "identity matrix"
        ]
      ],
      "raw_glosses": [
        "(linear algebra) An identity matrix"
      ],
      "topics": [
        "linear-algebra",
        "mathematics",
        "sciences"
      ]
    }
  ],
  "word": "unit matrix"
}