- 孤军奋战 gūjūnfènzhàn to fight a lone battleAn isolated army fighting bravely without reinforcements
- 孤军作战 gūjūnzuòzhàn to fight in isolationa lonely army fighting a hard battle without reinforcements or help
- 孤军深入 gūjūnshēnrù to penetrate deep into enemy territory aloneAn isolated force penetrating deep into enemy territory without reinforcements
- 四行孤军 sìhánggūjūn Lost Battalionthe group of Chinese soldiers who defended Sihang Warehouse during the Battle of Shanghai in 1937, also known as the Eight Hundred Heroes