How long does it take a society to learn a new term?
In this paper, I study the diffusion of new terms, called neologism, in social networks. I consider it as an example of information dynamics on networks and I hope that solving this problem can help us to understand and describe the information dynamics problem. To do so I develop a phenomenological model for the diffusion mechanism. I find an analytical relationship between number of people in the society who has learned the term and time taken. The Network parameters are imported in this analytical solution. I also present some simulation for this mechanism for several sample and some real networks which confirms the analytical results. In addition, I study the effects of network topology on diffusion process.