concern

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To have to do with or relate to.
• intransitive verb To be of interest or importance to.
• intransitive verb To engage the attention of; involve.
• intransitive verb To cause anxiety or uneasiness in.
• intransitive verb To be of importance.
• noun A matter that relates to or affects one.
• noun Regard for or interest in someone or something.
• noun A troubled or anxious state of mind.
• noun A business establishment or enterprise; a firm.

from The Century Dictionary.

• To relate or pertain to; have an intimate relation to or connection with.
• To affect the interest of; have interest for; be of importance to.
• To interest; busy; occupy; engage: used reflexively or in the passive voice: as, to concern one's self in the affairs of others; I was not concerned in that transaction.
• To disturb; make uneasy or anxious; cause disquiet to; trouble: generally in the past participle: as, to be deeply concerned about the safety of a friend.
• To confuse with drink; slightly intoxicate: in the past participle.
• Synonyms To interest, touch, affect.
• noun That which relates or pertains to one; matter of concernment; business; affair.
• noun Interest; matter of importance; that which affects one's welfare or happiness.
• noun Solicitous regard; solicitude; anxiety; agitation or uneasiness of mind; disturbed state of feeling; trouble.
• noun An establishment or firm for the transaction of business; a manufacturing or commercial establishment; a business house.
• noun A material object, especially one that is complicated or large; a contrivance: with a touch of depreciation.
• noun Synonyms Solicitude, etc. (see care); Concern at, about, for (see unconcerned); carefulness, thoughtfulness.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb obsolete To be of importance.
• transitive verb To relate or belong to; to have reference to or connection with; to affect the interest of; to be of importance to.
• transitive verb To engage by feeling or sentiment; to interest.
• noun That which relates or belongs to one; business; affair.
• noun That which affects the welfare or happiness; interest; moment.
• noun Interest in, or care for, any person or thing; regard; solicitude; anxiety.
• noun (Com.) Persons connected in business; a firm and its business.
• noun all connected with a particular affair or business.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun That which affects one's welfare or happiness
• noun The expression of solicitude, anxiety, or compassion toward a thing or person.
• noun A business, firm or enterprise; a company.
• verb transitive To be of importance to.
• verb transitive To make somebody worried.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun something or someone that causes anxiety; a source of unhappiness
• verb be on the mind of
• noun a feeling of sympathy for someone or something
• noun an anxious feeling
• noun something that interests you because it is important or affects you
• verb be relevant to
• noun a commercial or industrial enterprise and the people who constitute it