BIT ON THE SIDE BRIT.
Meaning of BIT ON THE SIDE BRIT. in English
bit on the side Brit.
informal
1》 a person with whom one is unfaithful to one's partner.
2》 money earned outside one's normal job.
→ bit
Concise Oxford English vocab.
Сжатый оксфордский словарь английского языка.
2004