本初子午線 [－－－－线]

Jyutping bun2 co1 zi2 ng5 sin3
Pinyin běn chū zǐ wǔ xiàn

Definitions (CC-CEDICT)
  1. the first meridian
  2. the prime meridian
Definitions (Wiktionary)
  1. noun
    prime meridian
    (syn.) 首子午線, 首子午线