The answer to this question is in the glossary. The word glossary comes from the Latin glossarium, which is made up of the words glossa, which means "dark, obsolete, or foreign word that requires an explanation," and the suffix -arium, which can be simply translated as a place to put or keep things in. A glossary, therefore, is a list, in alphabetical order, of those words that are difficult to understand in a text accompanied by their definitions or meanings.