1. A search system for searching for electronic documents, and providing a search result in response to a search query, comprising: a processor; a terms database, wherein terms in the terms database are grouped in a cluster based on the terms belonging to a same canonical word sense; a user interface module adapted to receive a search query from a user, said search query having at least one search query term and to allow a user to add at least one user defined sense to said search system for said one query term; a query processing module that determines a canonical word sense for the at least one search query term, and wherein said user interface module is adapted to display alternative senses in which said search query term is used, and to allow the user to select at least one of the alternative word senses, and wherein the query processing module identifies a plurality of alternative terms from a cluster based on the sense selected by the user; a search engine that electronically searches for electronic documents that satisfy said at least one search query term and said plurality of alternative terms; wherein the query processing module provides said plurality of alternative terms to said user interface module for display to the user, and wherein said user interface module is further adapted to display search results received from the search engine.