半路殺出個程咬金

1. • lit. Cheng Yaojin ambushes the enemy (saying)
2. • fig. sb shows up unexpectedly and disrupts the plan
3. • sb whose presence is regarded as irksome

Character by character

• 半(bàn)half
• 路(lù)surname Lu
• 殺(shā)kill
• 出(chū)go out
• 個(gè)(classifier used before a noun that has no specific classifier)
• 程(chéng)surname Cheng
• 咬(yǎo)bite
• 金(jīn)surname Jin