Noah Webster's Dictionary (n.) The quality or state of being perfect; perfection.

Multi-Version Concordance Perfectness (2 Occurrences) Colossians 3:14 And above all these things put on charity, which is the bond of perfectness. (KJV ASV DBY WBS) Joshua 24:14 And now fear Jehovah and serve him in perfectness and in truth; and put away the gods which your fathers served on the other side of the river, and in Egypt; and serve Jehovah. (DBY)