A gloss (from Koine Greek γλώσσα glossa, meaning 'tongue') is a note made in the margins or between the lines of a book, in which the meaning of the text in its original language is explained, sometimes in another language. As such, glosses can vary in thoroughness and complexity, from simple marginal notations of words one reader found difficult or obscure, to entire interlinear translations of the original text and cross references to similar passages. A collection of glosses is a glossary (though glossary also means simply a collection of specialised terms with their meanings). A collection of mediaeval legal glosses, made by so called glossators, commenting legal texts, is called an apparatus. The compilation of glosses into glossaries was the beginning of lexicography, and the glossaries so compiled were in fact the first dictionaries.