I read in a cd booklet that Beethoven was mostly educated autodidactically and, not knowing what that meant, decided to look it up. It wasn’t in my dictionary, so I tried it online. I cannot find the definition anywhere. However, there were quite a few uses of the word on people’s web pages, such as someone learning the guitar autodidactically. From the contexts the word has been used in, I’m guessing it means something like, learned by oneself or not in an actual institution.
Is this right? And, if the word is still used, why isn’t it in dictionaries?