When a term is used in its entire extent, referring to all the objects denoted by it, it is said to be

A term used in its whole extension, standing for all objects it denotes, is said to be distributed.

Distribution asks whether a proposition refers to every member of a term's class.

When the entire class is covered, the term is distributed.

When only a part is covered, it is undistributed.

Complete coverage of a term's denotation is the definition of distribution.