You can enable it by typing in chrome://flags/#contextual-search then pressing Enter. Once you enable it relaunch the browser, you’ll be able to tap individual words on a page then hit the icon for further information. Curiously, the page doesn’t exist yet, but we’re eagerly expecting that will be more explicit about this feature’s existence when it’s ready for the public. For now, you can at least have it ready for when makes it official.