Since As the definition and characteristics of semantics suggest, semantics is one of the most diverse fields within linguistics and there are defferent topixd and different methods in semantic study. In this chapter, we are concerned frimarily with semantics. One of the main concerns of semantics is to identify the governing principles that account for the nature of meaning. Then, it is worthwhile mentioning some of the most improtant semantic theories which ard keys to understanding how semantic study words.