class.
noun
Definitions
The act of forming into a class or classes; a distribution into groups, as classes, orders, families, etc., according to some common relations or attributes.
verb
Definitions
To identify by or divide into classes; to categorize
Example: Should we classify "make up" as an idiom or as a phrasal verb?
To declare something a secret, especially a government secret
Example: They decided to classify that information.