adjective
Statistics1Spread out to a greater degree or more evenly scattered than usual or expected; more evenly distributed than would be predicted as the result of random distribution; exhibiting or characterized by overdispersal.
2Exhibiting or characterized by statistical overdispersion; more unevenly distributed than would be the case if each instance were independent of the rest; clustered, aggregated; (of a distribution) having a variance greater than that predicted on the basis of independence and homogeneity.
Origin
1930s; earliest use found in Science. From over- + dispersed, after overdispersion.
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