A semantic network represents semantic relations among concepts, two concepts being related if their meanings are related. This is often used as a form of knowledge representation and can be modeled by a directed or undirected graph consisting of vertices that represent concepts and edges joining related concepts. Building a two-step synonym graph for computation with word semantics in Mathematica 8 is relatively straightforward using the function WordData, which holds interrelated information on nearly 150,000 words.
This Demonstration shows semantic networks corresponding to a selection of words that are in alphabetical order. A word was chosen by its first letter and then the size of its synonym graph, increasing by one for each letter of the alphabet. So "attendance" is the first of those words, starting with "a" and having a graph with three vertices; the next is "basement" starting with "b" with four vertices, and so on. Alas, there were no words starting with "x", "y", and "z" with 26, 27, and 28 vertices.