Macmillan's new Open Dictionary allows anyone to suggest definitions for new words, similar to online Urban Dictionary. It differs in the fact that the definitions are carefully screened and handpicked, making it — in theory — more reliable and trustworthy.
Language is a living thing and constantly changing. Open Dictionary features a host of current buzzwords, from neologisms to slang. Because the definitions are edited by Macmillian, explanations are clear and easy to understand. Even though the popular (and useful) Urban Dictionary contains way more selections than Open Dictionary, its descriptions are not always well-worded or clear. Urban Dictionary also relies on a democratic process in which definitions are voted up or down, which can be hit or miss.
The service feels pretty young and as such the list of vetted words is particularly small. Overall, Open Dictionary could be higher-quality resource than Urban Dictionary, but if nothing else it could be a nice companion for those times an Urban Dictionary's definition is a bit too inscrutable. Looking for more language tools? Check out our favourite online language resources.