本ほん初しょ子し午ご線せん

ほ

ん

しょ

し

ご

せ

ん

Meanings

1

noun

prime meridian

Geographical term for the 0° longitude line, specifically the one passing through Greenwich.

book, present, main

初first time, beginning

子child, sign of the rat, 11PM-1AM

午noon, sign of the horse, 11AM-1PM

線line, track

子し午ご線せん
子午線 is a general term for any meridian line, while 本初子午線 specifically refers to the prime meridian (0° longitude).

Compound of 本初 (ほんしょ, 'origin' or 'beginning') and 子午線 (しごせん, 'meridian'). The term is a direct translation of the English 'prime meridian'.