Lao Yuzi belongs to the northern language, Beijing dialect also has the word "Lao Yuzi", due to the different regions, the pronunciation is different, the meaning should be the same, in Mandarin, it is "old cunning".

[ 油子 ] yóu-zi

Beijing dialect. It refers to a cunning person who is rich in experience and familiar with the situation. It is also called "oil ladle".

References:

The Dictionary of the Mandarin Language

The Dictionary of the Beijing Native Language, No. 239

References:

The Beijing Native Language Dictionary.

Xu Shirong. A Dictionary of the Beijing Native Language by Xu Shirong