老油子

1. • wily old fox

     coll.

2. • crafty fellow

Character by character

• 老(lǎo)prefix used before the surname of a person or a numeral indicating the order of birth of the children in a family or to indicate affection or familiarity
• 油(yóu)oil
• 子(zi)noun suffix, as in 椅子 yǐzi "chair"