gistfile1.scala

package com.wordnik.client

import com.wordnik.client.api._
import com.wordnik.client.model._

import com.wordnik.swagger.runtime.common._

object Test {
  def main(args: Array[String]) = {
    val securityHandler = new ApiKeyAuthTokenBasedSecurityHandler("{YOUR_KEY}", null)
    APIInvoker.initialize(securityHandler, "http://api.wordnik.com/v4", false)
    val defInput = new WordDefinitionsInput
    defInput.word = "cat"
    WordAPI.getDefinitions(defInput).foreach(definition => println(definition.text))
  }
}

assumes you've built the swagger client per this gist:

https://gist.github.com/1249756