Previous research indicates that mental representations of word meanings are distributed along both semantic and syntactic dimensions such that nouns and verbs are relatively distinct from one another. Two experiments examined the effect of representational distance between meanings on recognition of ambiguous spoken words by comparing recognition of unambiguous words, noun-verb homonyms, and noun-noun homonyms. In Experiment 1, auditory lexical decision was fastest for unambiguous words, slower for noun-verb homonyms, and slowest for noun-noun homonyms. In Experiment 2, response times for matching spoken words to pictures followed the same pattern and eye fixation time courses revealed converging, gradual time course differences between conditions. These results indicate greater competition between meanings of ambiguous words when the meanings are from the same grammatical class (noun-noun homonyms) than when they are from different grammatical classes (noun-verb homonyms). Copyright © 2009 Cognitive Science Society, Inc. All rights reserved.