報ほう時じ球きゅう

noun

time ball

A historical maritime time-signaling device; a ball dropped at a set time to allow ships to calibrate their chronometers. Rare term; the more common word is 時球 (じきゅう).

See also: 時球

• 報ほう時じ球きゅうは、かつて港みなとで正しょう午ごを知しらせるために使つかわれた。

  Time balls were once used in ports to signal noon.