5.1.4 Psychological causesChanges o

5.1.4 Psychological causesChanges of meaning which spring from the mental state of particular speakers ,who have creatively extended the sense of words hy using them metaphorically, are manifold in language and this process will be considered in more detail in 5.2.1 However , there is a specific psychological cause of semantic change which is particularly powerful ( and which has been studied in detail ) : taboo 'Taboo' is a term which indicates a prohibition on the mention of a particular word, for a variety of reasons which vary from culture to culture but which show some inter-cultural constants ( see . for example Meillet 1921 ) . Since the concept related to a tabooed word nevertheless has to be referred to in some fashion, a frequent solution is to resort to a euphemism, that is, to a word or expression which for some reason can replace the tabooed item . It follows that a word used euphemistically undergoes semantic change in the form of an adition to its earlier sense or senses , but it is also probably the case that once a word's ;euphemistic' sense comes to be widely used, this fact prevents ( or at least militates against ) the word's use in its earlier sense, since speakers are likely to be unwilling to risk their non-euphemistic intention being interpreted in a euphemistic way . In other words , an expression which has acquired a new, euphemistic, sense is likely to rapidly lose its earlier, non-euphemistic,sense or senses . Examples of euphemism are frequently due to one or other of three types of taboo : fear taboo ( 5.1 4.1 ), delicacy taboo ( 5 . 1 . 4.2 ) , or decency taboo ( 5 . 1 . 4 . 3 ) .