iOS 5 has a ton of great features, but one that doesn’t get as much notice as I think it should is the great built-in dictionary! If you’ve ever wondered what a word means, now you don’t have to enter it into Google, or copy and paste. With just a couple of taps, you can see the definition of any word in almost any application that allows you to select text.
This only works in apps where you can select the word by itself, and of course not if the word is in an image file.
This is a handy little trick, I use it all the time to find the meanings of words. Words like, “plethora”.