圍城打援（圍城打援）　

◎ 圍城打援 wéichéng-dǎyuán

[besiege a city to annihilate the enemy relief force;besiege the enemy in order to strike at his reinforcements] 一種作戰(zhàn)方略。一部兵力包圍并佯攻敵城,另設伏兵攻打殲滅聞訊前來解圍的城外援敵