It is nice to have definition tooltips for original language words in Bibles. It would be nice also to have definition tooltips for English words in other resources. For instance, if I am reading about Roman history and encounter words such as Principate, praetor, or equestrian, I would like to be able to see a definition by hovering on the word. This could be achieved by linking up to one of the concise English dictionaries such as the Oxford's. In essence, this would be doing what double-clicking on the word does already, except that it would be interruptive of the reading experience.
