Definition of "close up"

(intransitive) To close (remove a gap) completely or fully.  examples

(intransitive) To move nearer together so that a gap is removed.  examples

(transitive, intransitive) To shut a building or a business for a period of time.  examples

(intransitive) Of a cut or other wound: To heal.  examples

(intransitive) To become less 'open' or communicative; to shrink back.  examples