Just. Wikipedia. It.
Random Person #1: Hey what the hell is a neutrino?
Random Person #2: JWI.
Just Wiki It.
Like JFGI (Just Fucking Google It) except for Wikipedia.
For quick definitions or explanations when there is no need for referencing or specific detail, when you just cannot be bothered to explain it to someone.
Person A: What's antidisestablishmentarianism?
Person B: JWI!