Calculatorbot has received some updates in the last couple of days. Now in addition to handling math problems, it can look up the definitions of words for you.
For example, I tweeted “@calculatorbot define capricious” and calculatorbot responded “http://xr.com/d4es capricious: (2 defns) Adjective: determined by chance or impulse or whim rather than by necessity or reason”
Calculatorbot includes a url to the word’s definition and the first definition of the word in its reply. Also note that the url returned is a shortened url.