OED I. 1. The relation of being objectively concerned in something, by having a right or title to, a claim upon, or a share in.
a. The fact or relation of being legally concerned; legal concern in a thing; esp. right or title to property, or to some of the uses or benefits pertaining to property.
e. esp. A pecuniary share or stake in, or claim upon anything; the relation of being a part-owner of property, a shareholder or bondholder in a commercial or financial undertaking, or the likej.
2.a. The relation of being concerned or affected in respect of advantage or detriment; esp. an advantageous relation of this kind.
3. A thing in which one has an interest or concern.
4. A business, cause, or principle, in which a number of persons are interested; the party interested in such a business or principle; a party having a common interest; a religious or political party, business connection, etc.
5. Regard to one's own profit or advantage; selfish pursuit of one's own welfare (as in self-interest)
7a. The feeling of one who is concerned or has a personal concern in any thing; hence, the state of feeling proper to such a relation, or a particular form or instance of it; a feeling of concern for or curiosity about a person or thing.
7b. transf. of things: Power of exciting this feeling, interesting character or quality.
8. The fact or quality of mattering or being of importance (as belonging to things); concernment, importance.