I.
noun
ADJECTIVE
▪ little , lucrative , nice , profitable , useful (all esp. BrE )
▪
He decided to turn his hobby into a lucrative ~.
▪
He had found himself a nice little ~ painting windows.
VERB + SIDELINE
▪ have
▪ develop
PREPOSITION
▪ ~ for
▪
Cider-making was a ~ for many farmers.
▪ ~ in
▪
She is developing a nice little ~ in babysitting for friends.
▪ ~ to
▪
The restaurant started out as a ~ to his main business.
II.
verb
Sideline is used with these nouns as the subject: ↑ injury