classify
verb (classifies, classifying, classified) with object
arrange (a group of people or things) in classes or categories according to shared qualities or characteristics:
«グループなどに/…として» …を分類する, 類別する «into, in/as» ; …を等級に分ける (!しばしば受け身で)
e.g. mountain peaks are classified according to their shape.
assign (someone or something) to a particular class or category:
e.g. elements are usually classified as metals or nonmetals.
designate (documents or information) as officially secret or to which only authorized people may have access:
〈情報･文書など〉を機密扱いにする(↔ declassify)
e.g. government officials classified 6.3 million documents in 1992.
DERIVATIVES
classifiable | ˈˌklasəˈfīəbəl | adjective
classificatory | -fikəˌtôrē | adjective
ORIGIN
late 18th century: back-formation from classification, from French, from classe ‘class’, from Latin classis ‘division’.