concern

Concise Oxford English Dictionary © 2008 Oxford University Press:
concern/kənˈsɜːn/

▶verb

• 1 relate to; be about.

  ■ affect or involve.

• 2 worry (someone).

• 3 (be concerned with/to do something) regard it as important to do something.

▶noun

• 1 worry; anxiety.

• 2 a matter of interest or importance.

• 3 a business.

– phrases
as (or so) far as someone/thing is concerned as regards the interests or case of someone or something.
have no concern with have nothing to do with.
to whom it may concern used to address a reader whose identity is unknown.

– origin ME: from Fr. concerner or late L. concernere (in med. L. ‘be relevant to’), from con- (expressing intensive force) + cernere ‘sift, discern’.