It's just a typo in your edition (see for instance page 32 of this Google Books link).
By the way the adjective absurd comes from the Latin word absurdus, so it seems improbable that an older spelling would have an extra e.
Edit: I've also found the version with an extra version with an extra e.e:
Because these two versions exist, I can think of two explanations: either this is a subtle joke/play on words (referring to the childish or absurd variant), or it is just a plain typo. I'm inclined to think it is the latter.