'Briefness' definitions:

Definition of 'briefness'

From: WordNet
noun
The temporal property of being very short
noun
The attribute of being brief or fleeting [syn: brevity, briefness, transience]

Definition of 'Briefness'

From: GCIDE
  • Briefness \Brief"ness\ (br[=e]f"n[e^]s), n. The quality of being brief; brevity; conciseness in discourse or writing. [1913 Webster] Brier