Words have often been compared to living organisms. One of the first authors to develop this idea was the French linguist Arsène Darmesteter who wrote a book entitled La vie des mots étudiée dans leurs significations (Darmesteter, 1887). He described the evolution of the meanings of words as a 'struggle for life' (concurrence vitale in his own words). To stay alive, words need to occupy as much 'semantic ground' as possible, particularly by taking over 'territories' in new semantic domains, creating thus the important phenomenon of polysemy (see also Bréal, 1897). Some words enjoy real 'success stories', expanding their meanings in many different directions, in a rather monopolistic way, while others decline and eventually die. Even though Darmesteter was more concerned by the analogy with biology rather than with social sciences, it is interesting to notice that his conception of interactions between words as a 'struggle for life' could also be applied to many social, political and economical human interactions. As a matter of fact, words are organized in the lexicon as a complex network of evolving semantic relations. It is not surprising that such a system shares