I have the Kindle Fire, and have a lot of books purchased. My wife got an iPad some time ago. I loaded the Kindle app on that, and transferred several of the books I already bought to that for her to read.
The iPad has the same sort of system for looking up words…just hold on the word and the dictionary pops up.
Unfortunately, while this works on the iBooks, it does not on the Kindle books on her iPad.
I am wondering if there is some app that will let this work on Kindle books on the iPad, or some procedure to make it work.
There should be a dictionary for the kindle ipad app. The amazon website indicates that if you tap and hold the word the dictionary definition should show up.
And try downloading a dictionary from within the Kindle store or your personal cloud. They’re free, but not always automatically downloaded to the individual Kindle devices unless you request them.