子午線(しごせん)

しごせん
noun
meridian; line of longitude
geography
1. meridian; line of longitude
An imaginary line running from the North Pole to the South Pole on the Earth's surface, used to measure longitude. The prime meridian passes through Greenwich, England.
日本(にほん)は東経(とうけい)135度(ど)の子午線(しごせん)が通(とお)っている。
The 135-degree east meridian passes through Japan.
本初(ほんしょ)子午線(しごせん)はグリニッジを通(とお)る。
The prime meridian passes through Greenwich.
明石市(あかしし)は日本(にほん)標準時(ひょうじゅんじ)子午線(しごせん)の町(まち)として知(し)られている。
Akashi is known as the city of the Japan Standard Time meridian.

Composed of 子(し) (rat, north) + 午(ご) (horse, south) + 線(せん) (line). The name comes from the Chinese zodiac directional system where 子(ね) represents north and 午(うま) represents south, so a 子午線(しごせん) is literally a north-south line.

Common collocations

  • 本初(ほんしょ)子午線(しごせん): prime meridian (0 degrees longitude)
  • 日本標準時(にほんひょうじゅんじ)子午線(しごせん): Japan Standard Time meridian (135 degrees east)
  • 子午線(しごせん)が通(とお)る: a meridian passes through

Cultural note

明石市(あかしし) in 兵庫県(ひょうごけん) is famous as the location where the 135th east meridian passes, which defines Japan Standard Time (JST). The city has a 子午線(しごせん) monument and a science museum dedicated to time.

Related words

Related Words

Related: 経線(けいせん) (line of longitude -- more technical…)
Related: 緯線(いせん) (line of latitude -- runs east-west)
Related: 赤道(せきどう) (equator)
general
Added 2026.4.29 20:20 · Revised 2026.9.2 13:02
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