Interest  —n. 1 a concern; curiosity (have no interest in fishing). B quality exciting curiosity etc. (this book lacks interest). 2 subject, hobby, etc., in which one is concerned. 3 advantage or profit (it is in my interest to go). 4 money paid for the use of money lent. 5 a thing in which one has a stake or concern (business interests). B financial stake (in an undertaking etc.). C legal concern, title, or right (in property). 6 a party or group with a common interest (the brewing interest). B principle or cause with which this is concerned. —v. 1 excite the curiosity or attention of. 2 (usu. Foll. By in) cause (a person) to take a personal interest. 3 (as interested adj.) Having a private interest; not impartial or disinterested. [latin, = it matters]