This chapter explores the widespread phenomenon of semantic secularization. An example of an ideologically-neutral semantic secularization is visible in the transition of the meaning for the English word cell from ‘monk’s living place’ to become instead ‘autonomous self-replicating unit from which tissues of the body are formed’. The main focus of this chapter, however, is on secularizations involving ideological what I call ‘lexical engineering’, as exemplified by deliberate, subversive processes of extreme semantic shifting, pejoration, amelioration, trivialization, and allusion. An example of such transvaluation, the transition of semantic value, is [bəloˈri:t]. In Mishnaic Hebrew this term means ‘Mohawk, an upright strip of hair that runs across the crown of the head from the forehead to the nape of the neck’, a distinctive of the abominable pagan and not to be touched by the Jewish barber. But, defying religious values as well as negating the Diaspora (where Jews by and large had tidy hair), secular Socialist Zionists use blorít with the meaning ‘forelock, hair above the forehead’, which becomes one of the defining characteristics of the ‘Sabra’ (‘prickly pear’ a metaphor for a native Israeli)—as if proposing that the ‘new Jew’ is a pagan. In line with the prediction made by Gershom Scholem in his famous letter to Franz Rosenzweig (Bekenntnis über unsere Sprache, 1926), some ultra-orthodox Jews have tried to launch a ‘lexical vendetta’: using secularized terms as dormant agents, as a shortcut to religious concepts, thus trying to convince secular Jews to go back to their religious roots.