Anyway, along with definitions, you mention the first Myth book by Asprin. Many years ago I really enjoyed those books. I'm not sure I would call them humor as in laugh-out loud, but they are definitely light, easy reads.
I used to call them bubble-gum reading. Something that was sweet and didn't take too much work to read or enjoy; however, not a lot of meat to them.
He also has (had, since he passed away) a series about Phule's army that was an enjoyable read. You might describe it as humorous or silly. I thought the jokes were a little too obvious to be truly LOL funny, but I found them quite amusing.