Universally taboos and metaphors are very often in a reciprocal relationship, in that generally the former originate from the latter. In this relationship they very often trigger both semantic and lexical variations, that synchronically are distributed among diverse contexts and diachronically are a fertile source of language change. Euphemism plays an important role here, and receives special attention. This paper focuses on the most significant impact of these phenomena on the language change, as observed in Latin and in the modern languages, particularly when looked at from a synchronic and a diachronic perspective. In this respect, we analyse the socio-cultural factors behind the use of metaphors connected with taboos, taking into account their semantical-functional classification. We look at several aspects of the question, such as cycles of semantic reinforcement and weakening and the discursive strategies for pragmatic and argumentative purposes, such as politeness, mitigation, irony.