What's the correct option?
I (have) learned that word from books.
Maybe there's something funny with this sentence? Maybe you can learn a word only from one book? I'm assuming this based on this Google search.
Personally, I would say have learned because it makes it sound like you learned it at an indefinite that was in the past. However, saying that you just learned it sounds better to me when you're talking about a specific book. I.e.
I have learned it from books. (over time, at some time in the past)
I learned it from the Bible. (a specific book that you read once)
However, I learned it from books still sounds decently good.