Some psychologically salient meaning properties of lexical items were isolated using judgments about the similarity of meaning within three sets of words: verbs of judging, hypothetical verbs, and locative prepositions. Subjects were asked to rate the similarity of meaning of all possible pairs of words from one of the three domains on a 1-9 scale. These ratings were analyzed by a hierarchical clustering technique. In addition to the usual hierarchical clustering solution, a cohesion score was calculated which indicated how tightly bound a particular cluster was. The results for verbs of judging and prepositions were consistent with those reported by Fillenbaum and Rapoport (1971). In all cases the results were highly interpretable and intuitively satisfying. The verbs of judging were polarized along a good-bad dimension; the salient properties for the hypothetical verbs concerned predictions about the occurrence of uncertain events; and the locative prepositions focused on the deictic relationship between an individual and a three-dimensional object. As a background to the experimental study the possible organization of the lexicon is discussed from both the linguistic and psychological points of view. (Author)