"緯線" meaning in Japanese

{
  "forms": [
    {
      "form": "緯線",
      "ruby": [
        [
          "緯",
          "い"
        ],
        [
          "線",
          "せん"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "isen",
      "tags": [
        "romanization"
      ]
    },
    {
      "form": "wisen",
      "tags": [
        "romanization"
      ]
    },
    {
      "form": "ゐせん",
      "roman": "wisen",
      "tags": [
        "hiragana",
        "historical"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "いせん",
        "hhira": "ゐせん"
      },
      "expansion": "緯(い)線(せん) • (isen) ^(←ゐせん (wisen)?)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Japanese entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese links with redundant alt parameters",
          "parents": [
            "Links with redundant alt parameters",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese links with redundant wikilinks",
          "parents": [
            "Links with redundant wikilinks",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms suffixed with 線",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with redundant sortkeys",
          "parents": [
            "Terms with redundant sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "ja",
          "name": "Geography",
          "orig": "ja:Geography",
          "parents": [
            "Earth sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "a parallel, a latitude (imaginary line parallel to the equator)"
      ],
      "id": "en-緯線-ja-noun-uI3uUvdY",
      "links": [
        [
          "parallel",
          "parallel"
        ],
        [
          "latitude",
          "latitude"
        ]
      ],
      "related": [
        {
          "roman": "ido",
          "ruby": [
            [
              "緯",
              "い"
            ],
            [
              "度",
              "ど"
            ]
          ],
          "word": "緯度"
        },
        {
          "roman": "keisen",
          "ruby": [
            [
              "経",
              "けい"
            ],
            [
              "線",
              "せん"
            ]
          ],
          "word": "経線"
        },
        {
          "roman": "sekidō",
          "ruby": [
            [
              "赤",
              "せき"
            ],
            [
              "道",
              "どう"
            ]
          ],
          "word": "赤道"
        }
      ],
      "wikipedia": [
        "ja:緯線"
      ]
    }
  ],
  "sounds": [
    {
      "other": "いせん"
    },
    {
      "ipa": "[isẽ̞ɴ]"
    }
  ],
  "word": "緯線"
}

{
  "forms": [
    {
      "form": "緯線",
      "ruby": [
        [
          "緯",
          "い"
        ],
        [
          "線",
          "せん"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "isen",
      "tags": [
        "romanization"
      ]
    },
    {
      "form": "wisen",
      "tags": [
        "romanization"
      ]
    },
    {
      "form": "ゐせん",
      "roman": "wisen",
      "tags": [
        "hiragana",
        "historical"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "いせん",
        "hhira": "ゐせん"
      },
      "expansion": "緯(い)線(せん) • (isen) ^(←ゐせん (wisen)?)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "related": [
    {
      "roman": "ido",
      "ruby": [
        [
          "緯",
          "い"
        ],
        [
          "度",
          "ど"
        ]
      ],
      "word": "緯度"
    },
    {
      "roman": "keisen",
      "ruby": [
        [
          "経",
          "けい"
        ],
        [
          "線",
          "せん"
        ]
      ],
      "word": "経線"
    },
    {
      "roman": "sekidō",
      "ruby": [
        [
          "赤",
          "せき"
        ],
        [
          "道",
          "どう"
        ]
      ],
      "word": "赤道"
    }
  ],
  "senses": [
    {
      "categories": [
        "Japanese entries with incorrect language header",
        "Japanese lemmas",
        "Japanese links with redundant alt parameters",
        "Japanese links with redundant wikilinks",
        "Japanese nouns",
        "Japanese terms historically spelled with ゐ",
        "Japanese terms spelled with second grade kanji",
        "Japanese terms spelled with secondary school kanji",
        "Japanese terms suffixed with 線",
        "Japanese terms with IPA pronunciation",
        "Japanese terms with non-redundant non-automated sortkeys",
        "Japanese terms with redundant sortkeys",
        "Japanese terms written with two Han script characters",
        "ja:Geography"
      ],
      "glosses": [
        "a parallel, a latitude (imaginary line parallel to the equator)"
      ],
      "links": [
        [
          "parallel",
          "parallel"
        ],
        [
          "latitude",
          "latitude"
        ]
      ],
      "wikipedia": [
        "ja:緯線"
      ]
    }
  ],
  "sounds": [
    {
      "other": "いせん"
    },
    {
      "ipa": "[isẽ̞ɴ]"
    }
  ],
  "word": "緯線"
}