Classification/ˌklæsɪfɪˈkeɪʃn/ Definition 1 of 3Pro Tip 1/3Library Use In libraries, 'classification' is often about organizing books by subject and author. She found the novel by its classification under 'M' for mystery. Pro Tip 2/3Group Similar 'Classification' groups things that share characteristics, like sorting fruits by color. Their classification grouped all red fruits together. Pro Tip 3/3Hierarchy Unrelated Classification isn't about creating a hierarchy; it's about grouping, not ranking. Classifying animals doesn't mean one is better than the other.