to be about or involve someone or something
This notice concerns all employees about the new policy.
to be about a topic
The book's first chapter concerns the early history of the city.
to make someone worried
Your health problems concern me, and I think you should see a doctor.
to show interest in something
He doesn't concern himself with small details that don't matter.
a feeling of worry
There is growing concern about the safety of the building after the earthquake.
care and help for someone or something
She showed great concern for her sick friend by visiting every day.
something that is important to someone
Our main concern is to provide good education for all children.
something that is your business or responsibility
How I spend my money is not your concern, so please don't ask.
a company or business
The large business concern announced it would create new jobs in the area.