'Terribleness' definitions:

Definition of 'terribleness'

noun

A quality of extreme unpleasantness [syn: awfulness, dreadfulness, horridness, terribleness]

From: GCIDE

Terrible \Ter"ri*ble\, a. [F., fr. L. terribilis, fr. terrere to frighten. See Terror.]
1. Adapted or likely to excite terror, awe, or dread; dreadful; formidable. [1913 Webster]
Prudent in peace, and terrible in war. --Prior. [1913 Webster]
Thou shalt not be affrighted at them; for the Lord thy God is among you, a mighty God and terrible. --Deut. vii. 21. [1913 Webster]
2. Excessive; extreme; severe. [Colloq.] [1913 Webster]
The terrible coldness of the season. --Clarendon. [1913 Webster]
Syn: Terrific; fearful; frightful; formidable; dreadful; horrible; shocking; awful. [1913 Webster] -- {Ter"ri*ble*ness}, n. -- {Ter"ri*bly}, adv. [1913 Webster]