"赤線" meaning in Japanese

{
  "forms": [
    {
      "form": "赤線",
      "ruby": [
        [
          "赤",
          "あか"
        ],
        [
          "線",
          "せん"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "akasen",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "あかせん"
      },
      "expansion": "赤(あか)線(せん) • (akasen)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "related": [
    {
      "_dis1": "0 0",
      "roman": "aosen",
      "ruby": [
        [
          "青線",
          "あおせん"
        ]
      ],
      "word": "青線"
    }
  ],
  "senses": [
    {
      "glosses": [
        "red line"
      ],
      "id": "en-赤線-ja-noun-oLzJa42N",
      "links": [
        [
          "red",
          "red"
        ],
        [
          "line",
          "line"
        ]
      ]
    },
    {
      "alt_of": [
        {
          "extra": "(akasenchitai): Akasen (districts in Japan where prostitution and the sex industry flourished)",
          "word": "赤線地帯(あかせんちたい)"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "Japanese terms with non-redundant non-automated sortkeys",
          "parents": [],
          "source": "w"
        },
        {
          "_dis": "25 75",
          "kind": "other",
          "name": "Japanese entries with incorrect language header",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "24 76",
          "kind": "other",
          "name": "Japanese links with redundant alt parameters",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "14 86",
          "kind": "other",
          "name": "Japanese links with redundant wikilinks",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "36 64",
          "kind": "other",
          "name": "Japanese terms with 2 kanji",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "14 86",
          "kind": "other",
          "name": "Japanese terms with redundant sortkeys",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "13 87",
          "kind": "other",
          "name": "Pages with 2 entries",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "7 93",
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "Short for 赤線地帯(あかせんちたい) (akasenchitai): Akasen (districts in Japan where prostitution and the sex industry flourished)"
      ],
      "id": "en-赤線-ja-noun-PBAtTorW",
      "links": [
        [
          "赤線地帯(あかせんちたい)",
          "赤線地帯#Japanese"
        ]
      ],
      "raw_glosses": [
        "(historical) Short for 赤線地帯(あかせんちたい) (akasenchitai): Akasen (districts in Japan where prostitution and the sex industry flourished)"
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "historical"
      ]
    }
  ],
  "sounds": [
    {
      "other": "あかせん"
    },
    {
      "ipa": "[a̠ka̠sẽ̞ɴ]"
    }
  ],
  "wikipedia": [
    "ja:赤線"
  ],
  "word": "赤線"
}

{
  "categories": [
    "Japanese entries with incorrect language header",
    "Japanese lemmas",
    "Japanese links with redundant alt parameters",
    "Japanese links with redundant wikilinks",
    "Japanese nouns",
    "Japanese terms spelled with first grade kanji",
    "Japanese terms spelled with second grade kanji",
    "Japanese terms with 2 kanji",
    "Japanese terms with IPA pronunciation",
    "Japanese terms with redundant sortkeys",
    "Pages with 2 entries",
    "Pages with entries"
  ],
  "forms": [
    {
      "form": "赤線",
      "ruby": [
        [
          "赤",
          "あか"
        ],
        [
          "線",
          "せん"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "akasen",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "あかせん"
      },
      "expansion": "赤(あか)線(せん) • (akasen)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "related": [
    {
      "roman": "aosen",
      "ruby": [
        [
          "青線",
          "あおせん"
        ]
      ],
      "word": "青線"
    }
  ],
  "senses": [
    {
      "glosses": [
        "red line"
      ],
      "links": [
        [
          "red",
          "red"
        ],
        [
          "line",
          "line"
        ]
      ]
    },
    {
      "alt_of": [
        {
          "extra": "(akasenchitai): Akasen (districts in Japan where prostitution and the sex industry flourished)",
          "word": "赤線地帯(あかせんちたい)"
        }
      ],
      "categories": [
        "Japanese terms with historical senses",
        "Japanese terms with non-redundant non-automated sortkeys"
      ],
      "glosses": [
        "Short for 赤線地帯(あかせんちたい) (akasenchitai): Akasen (districts in Japan where prostitution and the sex industry flourished)"
      ],
      "links": [
        [
          "赤線地帯(あかせんちたい)",
          "赤線地帯#Japanese"
        ]
      ],
      "raw_glosses": [
        "(historical) Short for 赤線地帯(あかせんちたい) (akasenchitai): Akasen (districts in Japan where prostitution and the sex industry flourished)"
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "historical"
      ]
    }
  ],
  "sounds": [
    {
      "other": "あかせん"
    },
    {
      "ipa": "[a̠ka̠sẽ̞ɴ]"
    }
  ],
  "wikipedia": [
    "ja:赤線"
  ],
  "word": "赤線"
}

{
  "called_from": "parser/1336",
  "msg": "no corresponding start tag found for </span>",
  "path": [
    "赤線"
  ],
  "section": "Japanese",
  "subsection": "noun",
  "title": "赤線",
  "trace": ""
}

{
  "called_from": "form_descriptions/2278",
  "msg": "suspicious alt_of/form_of with '(': 赤線地帯(あかせんちたい)",
  "path": [
    "赤線"
  ],
  "section": "Japanese",
  "subsection": "noun",
  "title": "赤線",
  "trace": ""
}