"基線" meaning in 日本語

{
  "categories": [
    {
      "kind": "other",
      "name": "日本語",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "日本語 名詞",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "日本語 国際音声記号あり",
      "parents": [],
      "source": "w"
    }
  ],
  "forms": [
    {
      "form": "きせん"
    }
  ],
  "lang": "日本語",
  "lang_code": "ja",
  "pos": "noun",
  "pos_title": "名詞",
  "senses": [
    {
      "glosses": [
        "三角測量などで基準となる直線。"
      ],
      "id": "ja-基線-ja-noun-I6PBQ5Zy"
    },
    {
      "categories": [
        {
          "kind": "other",
          "name": "日本語 地理",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "領海、接続水域、排他的経済水域、大陸棚の幅を測定する際の基準となる線。"
      ],
      "id": "ja-基線-ja-noun-Y~~cs7XQ",
      "topics": [
        "geography"
      ]
    },
    {
      "categories": [
        {
          "kind": "other",
          "name": "日本語 幾何学",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "界線。"
      ],
      "id": "ja-基線-ja-noun-0IwozsvJ",
      "raw_tags": [
        "投影図"
      ],
      "topics": [
        "geometry"
      ]
    }
  ],
  "sounds": [
    {
      "form": "きせん",
      "raw_tags": [
        "東京式"
      ],
      "roman": "[kìséń]",
      "tags": [
        "Heiban"
      ]
    },
    {
      "ipa": "[kʲisẽ̞ɴ]"
    }
  ],
  "word": "基線"
}

{
  "categories": [
    "日本語",
    "日本語 名詞",
    "日本語 国際音声記号あり"
  ],
  "forms": [
    {
      "form": "きせん"
    }
  ],
  "lang": "日本語",
  "lang_code": "ja",
  "pos": "noun",
  "pos_title": "名詞",
  "senses": [
    {
      "glosses": [
        "三角測量などで基準となる直線。"
      ]
    },
    {
      "categories": [
        "日本語 地理"
      ],
      "glosses": [
        "領海、接続水域、排他的経済水域、大陸棚の幅を測定する際の基準となる線。"
      ],
      "topics": [
        "geography"
      ]
    },
    {
      "categories": [
        "日本語 幾何学"
      ],
      "glosses": [
        "界線。"
      ],
      "raw_tags": [
        "投影図"
      ],
      "topics": [
        "geometry"
      ]
    }
  ],
  "sounds": [
    {
      "form": "きせん",
      "raw_tags": [
        "東京式"
      ],
      "roman": "[kìséń]",
      "tags": [
        "Heiban"
      ]
    },
    {
      "ipa": "[kʲisẽ̞ɴ]"
    }
  ],
  "word": "基線"
}