1. A system for context-based disambiguation of abbreviations, comprising: a processor; an analyze passage module operable to execute on the processor and further operable to determine a target abbreviation and one or more keywords appearing in context with the target abbreviation in a received passage, the target abbreviation representing a shortened form of one or more word; a contextual search query generation component operable to generate a contextual search query comprising the target abbreviation and said one or more keywords; a search pseudo document index module operable to search a pseudo document index for one or more expansions of the target abbreviation by invoking the contextual search query, the pseudo document index containing index of one or more pseudo documents by titles, associated one or more abbreviations and associated context keywords, wherein the titles are the expansions of the abbreviations contained in the pseudo documents respectively, the search pseudo document index module further operable to return one or more pseudo documents associated with the target abbreviation based on the searching of the pseudo document index, wherein one or more expansions associated with the target abbreviation are provided based on the returned one or more target pseudo documents, wherein a pseudo document of said one or more pseudo documents is generated for an expansion in an abbreviation expansion dictionary by extracting data from sources that contain language occurring with the expansion; and a machine learning classification model generation module operable to determine the target abbreviation and one or more keywords appearing in context with the target abbreviation in a received passage, the machine learning classification model generating one or more features that capture lexical and syntactic properties of the passage, and recognizing said target abbreviation and said one or more keywords appearing in context with the target abbreviation in the received passage based on the captured lexical and syntactic properties.