Side Business, Second Job, Moonlighting
noun, verbal noun
Concurrently with my current business I have a side business. It's really a second job, actually.
けんぎょう
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
最近では、兼業ヤクザが増えてきています。
The amount of yakuza who have side jobs has been increasing lately.