A gloss (from Koine Greek γλώσσα glossa, meaning 'tongue'—the organ—as well as 'language') is a note mae 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.