Does Your Fiction Book Need a Glossary? Does Mine?

Ever read a work of fiction and wish it included a glossary of the book’s unusual terms and names? Or do you think of glossaries as useless wastes?

In General

More common in nonfiction, glossaries sometimes appear in science fiction and fantasy books, to help readers orient to the unfamiliar world of a novel bristling with strange words and numerous proper nouns.  

Daniel J. Tortora posted a nice discussion of glossaries giving you everything you need to know.

Your Context-Free Slang...