Semantic structure in the mental lexicon is often assumed to
follow a taxonomic structure grouping similar items. This
study uses a network clustering analysis of a massive word
association dataset that does not primarily focus on concrete
noun categories, but includes the majority of the words used
in daily life. At this scale, we found widespread overlap
between thematically organized clusters, arguing against a
discrete categoric view of the lexicon. An empirical analysis
focusing on taxonomic categories confirmed the widespread
thematic structure even for concrete noun categories in the
animal domain. Overall, this suggests that applying network
clustering to word association data provides valuable insight
into how large-scale semantic information is represented. This
analysis leads to a different, more thematic topology than the
one inferred from idealized small-scale approaches that sample
only specific parts of the lexicon