1.
ambush; hidden troops; soldiers lying in wait
Soldiers concealed in a strategic position to launch a surprise attack. A military tactic.
森の中に伏兵を置く。
To place an ambush in the forest.
敵の伏兵に襲われた。
We were attacked by enemy troops in ambush.
伏兵が待ち伏せしていることに気づかなかった。
We didn't realize that hidden troops were lying in ambush.
2.
dark horse; unexpected rival; hidden threat
An unexpected competitor, obstacle, or difficulty that catches someone off guard. Used figuratively in sports, business, and everyday situations.
思わぬ伏兵が現れた。
An unexpected rival appeared.
無名のチームが伏兵として優勝した。
An unknown team won as the dark horse.
試験の最後の問題が伏兵だった。
The last question on the exam was an unexpected challenge.
Originally a military term for soldiers hidden in ambush, now more commonly used figuratively to describe an unexpected threat, rival, or challenge that catches someone off guard.
COMMON COLLOCATIONS:
- 伏兵が現れる: an unexpected rival appears
- 思わぬ伏兵: an unforeseen obstacle/rival
- 伏兵を置く: to set an ambush
- 伏兵に襲われる: to be attacked by an ambush
USAGE:
The figurative sense (sense 2) is more common in modern Japanese. Often used in sports commentary to describe an underdog or unexpected contender, or in everyday conversation to describe a hidden difficulty or surprise obstacle.
ETYMOLOGY:
伏 (lie face down, hide) + 兵 (soldier) — soldiers who lie hidden.