There are multiple definitions - click on the translation that matches your context.

Schwarzarbeit

Substantiv

partial

moonlighting

noun

Comparative law notes

Germany

Since moonlighting can also refer to merely a second declared job, the term is not always completely analogous to the German "Schwarzarbeit".

Definitions of moonlighting

English

(informal) the activity of having a second job as well as your regular job, especially a job that you do secretly and in the evenings, at night, or weekends, and do not declare to the tax authorities

The number of Brits moonlighting to supplement their incomes has doubled in just twelve months.