They released an API a few months ago and I quickly threw together a gem wrapping it, based on HTTParty. Tonight I updated the gem for version 3 of the API and simplified it to just a single class with the bare essentials. You can perform pretty much all of the API calls and get a hash of the results. It’s nothing major, but will give you a chance to play around with the Wordnik API with almost no work on your part (aside from getting yourself a key). This change breaks backwards compatibility completely, sorry.
w = Wordnik.new("YOUR_API_KEY")
w.define('gem') # => big hash with all the definitions
w.examples('gem') # => example sentences using "gem"