This word is used in its proper sense in Deuteronomy 28:34, John 10:20, 1 Corinthians 14:23. It also denotes a reckless state of mind arising from various causes, as over-study (Eccl 1:17; 2:12), blind rage (Luke 6:11), or a depraved temper (Eccl 7:25; 9:3; 2Pet 2:16). David feigned madness (1 Samuel 21:13) at Gath because he "was sore afraid of Achish."
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Madness'". "Easton's Bible Dictionary".