Definitions of concern:

• noun:   something that interests you because it is important or affects you

  Example: "The safety of the ship is the captain's concern"

• noun:   something or someone that causes anxiety; a source of unhappiness

  Example: "New York traffic is a constant concern"

• noun:   a feeling of sympathy for someone or something

  Example: "She felt strong concern for those less fortunate"

• noun:   an anxious feeling
• noun:   a commercial or industrial enterprise and the people who constitute it

  Example: "A racially integrated business concern"

• verb:   be on the mind of
• verb:   have to do with or be relevant to