The problem and process of identifying the meaning of a word as per its usage context is called word sense disambiguation (WSD). Although research in this field has been ongoing for the past forty years, a distinct change of techniques adopted can be observed over time. Two important parameters govern the direction in which WSD research progresses during any period. These are the underlying requirement of the kind of sense disambiguation, or the domain, and the robustness of available knowledge in the form of corpora or dictionaries. This paper surveys the progress of WSD over time and the important linguistic achievements that enabled this progress.