"索" meaning in Japanese

{
  "categories": [],
  "forms": [
    {
      "form": "“Jōyō” kanji",
      "tags": [
        "common"
      ]
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "character",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Common kanji",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with non-redundant manual transliterations",
          "parents": [
            "Terms with non-redundant manual transliterations",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with redundant transliterations",
          "parents": [
            "Terms with redundant transliterations",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "derived": [
        {
          "english": "search, look up, retrieve",
          "roman": "kensaku",
          "ruby": [
            [
              "検索",
              "けんさく"
            ]
          ],
          "word": "検索"
        },
        {
          "english": "index",
          "roman": "sakuin",
          "ruby": [
            [
              "索引",
              "さくいん"
            ]
          ],
          "word": "索引"
        }
      ],
      "glosses": [
        "string, thread"
      ],
      "id": "en-索-ja-character-pWZwEEd1",
      "tags": [
        "kanji"
      ]
    }
  ],
  "word": "索"
}

{
  "categories": [
    "Middle Korean Han characters"
  ],
  "derived": [
    {
      "english": "search, look up, retrieve",
      "roman": "kensaku",
      "ruby": [
        [
          "検索",
          "けんさく"
        ]
      ],
      "word": "検索"
    },
    {
      "english": "index",
      "roman": "sakuin",
      "ruby": [
        [
          "索引",
          "さくいん"
        ]
      ],
      "word": "索引"
    }
  ],
  "forms": [
    {
      "form": "“Jōyō” kanji",
      "tags": [
        "common"
      ]
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "character",
  "senses": [
    {
      "categories": [
        "Common kanji",
        "Japanese Han characters",
        "Japanese kanji with goon reading さく",
        "Japanese kanji with goon reading しゃく",
        "Japanese kanji with kan'on reading さく",
        "Japanese kanji with kun reading なわ",
        "Japanese kanji with kun reading もと-める",
        "Japanese terms spelled with 索",
        "Japanese terms with non-redundant manual transliterations",
        "Japanese terms with redundant transliterations"
      ],
      "glosses": [
        "string, thread"
      ],
      "tags": [
        "kanji"
      ]
    }
  ],
  "word": "索"
}