- 老油子 lǎoyóuzi wily old fox(colloquial) A person who is very experienced and crafty; a smooth operator or wily campaigner who knows how to handle situations or avoid responsibility. Also written as [[老油条|老油條|lao3 you2 tiao2]].
- 兵油子 bīngyóuzi sly old soldier(colloquial) an old soldier who has stayed in the army for a long time and picked up bad habits
- 京油子 jīngyóuzi Beijing slickerA person who has lived in Beijing for a long time and is worldly, smooth-talking, and untrustworthy; usually carries a negative tone.
- 烟袋油子 yāndàiyóuzi tobacco tarThe sticky deposit of oil and grime accumulated inside a tobacco pipe; pipe tar.
- 走油子 zǒuyóuzi to ooze oilTo leak or ooze oil, specifically referring to a plaster or medical patch that has become too old and the ointment has started to seep out