I read cozy and historical mysteries, a bit of Paranormal/UF, and to mix it up, I read science and gardening books on occasion.
When I first picked up this book, I figured I'd flip through it, stopping at words that caught my eye along the way and be finished up with it in a few hours; it's a glossary, after all.
But then I discovered that each lettered section begins with the reproduction of a letter from the front; a man named Charles, writing to his parents, his brother and his nephew. These were good - they were better than good, they turned a freaking glossary into a narrative, and in addition to learning new words (and meanings for old words), I had to keep flipping so I could find out what happened to Charles next, always sure that I was going to get to 'Z' to find a bad news telegram or something. I didn't.
I knocked off 1/2 a star because, while Charles makes it to 'Z', you never find out what happens to him in the rest of the war. A letter at the very start makes it clear he survived, but with 2 years of the war left, 'Z' leaves the reader with something of a small cliffhanger.
Still, way better than your average glossary for readability!