SimTerm is a free tool that compares terms (nouns) based on their semantic relationship. SimTerm calculates the semantic resemblance between two terms using WordNet as a source that provides all the necessary information to perform the comparison.
SimTerm generates the shortest graph using the hyperonym-hyponym relationships between the terms defined in WordNet and applies three different measures.
PathLength: Measure based on counting the number of nodes along the shortest path between the senses in the WordNet taxonomy. Its range is [0, 1].
R. Rada, H. Mili, E. Bicknell, M. Blettener, “Development and Application of a Metric on Semantic Nets”, IEEE Transactions on Systems, Man and Cybernetics, 19, 1, 17-30, 1989.
Wu & Palmer: Measure based on the depth of the Least Common Subsumer of the terms in comparison as well as their relative depth in the WordNet Taxonomy. Its range is [0, 1].
Z. Wu, M. Palmer, “Verbs semantics and lexical selection”, Proc. 32nd annual meeting on Association for Computational Linguistics, 133-138, 1994.
Leacock & Chodorow: Measure that uses the maximum depth of WordNet taxonomy (20) for weighting the similarity between terms.
C. Leacock, M. Chodorow, “Combining local context and WordNet Similarity for Word Sense Identification.” In C. Fellbaum “WordNet: an electronic lexical database”. Ed. MIT, 1998.
SimTerm is a pretty easy-to-use tool. Just type the terms you'd like to compare and click the "Get senses" button...
Now choose the sense of the terms you want to use, press again the "Compare" button and... VOILÀ! You are done!