Tag clouds provide an excellent means of visualization of weighted semantic information. When, on the other hand, this information is not definitive but is rather accompanied by a measurable degree of uncertainty, conventional tag clouds are no longer suitable visualization tools. In this paper we extend the conventional approach to tag cloud generation and propose the utilization of the degree of opaqueness as a means to visualize the degree of certainty. In order to experimentally assess the efficacy of the proposed approach we have developed the corresponding software tools and have applied the conventional and proposed approached to tag visualization in a real life scenario of probabilistic data.