Using Lexipedia you can visually map out words and concepts in a clean and friendly interface. No more thumbing through a dictionary, or fumbling through a single-word search; with Lexipedia you can see related words, synonyms, antonyms and fuzzynyms. And best of all, it's absolutely free!
n.
the act of constituting a political unity out of a number of separate states or colonies or provinces so that each member retains the management of its internal affairs
n.
a center of activity or interest or commerce or transportation; a focal point around which events revolve; "the playground is the hub of parental supervision"; "the airport is the economic hub of the area"
n.
(ecology) a group of organisms (plants and animals) that live together in a certain geographical region and constitute a community with a few dominant species