One who is, is believed to be, or believes oneself to be an expert in some area, field, or topic. Anyone proclaiming to be a maven when it comes to dating or hooking up is just looking to take your money.You should talk to my cousin Jerry—he's a real maven in the stock market.
maven
and mavin (ˈmevnæ)
1. n. an expert; a self-proclaimed expert. (From Hebrew mevin via Yiddish.) A maven in the stock market you are not.
2. in. to act as a maven (sense 1). She’s always mavening about something.