noun
overseas trip; overseas expedition
Often used for sports teams, military units, or organized groups traveling abroad for a specific mission or competition.
サッカーチームは海外遠征に出発した。
The soccer team departed on an overseas tour.
来月、海外遠征でヨーロッパに行く予定だ。
Next month, I'm scheduled to go to Europe on an overseas expedition.
Compound of 海外 (overseas) and 遠征 (expedition, campaign).