noun
equator-crossing ceremony
A traditional maritime ceremony held when a ship crosses the equator, often involving playful initiation rituals for first-timers.
船が赤道を越えるとき、赤道祭が行われた。
When the ship crossed the equator, an equator-crossing ceremony was held.
Compound of 赤道 (sekidō, 'equator') + 祭 (sai, 'festival, ceremony').