King James Bible Dictionary

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 (Ecclesiastes 1:17; 2:12), blind rage (Luke 6:11), or a depraved temper (Ecclesiastes 7:25; 9:3; 2 Peter 2:16). David feigned madness (1 Samuel 21:13) at Gath because he "was sore afraid of Achish."

See Insanity
Insanity

In Scripture "madness" is recognized as a derangement proceeding either from weakness and misdirection of intellect or from ungovernable violence of passion. In one passage alone, (John 10:20) is madness expressly connected with demoniacal possession by the Jews in their cavil against our Lord; in none is it referred to any physical causes.

MAD'NESS, noun [from mad.] Distraction; a state of disordered reason or intellect, in which the patient raves or is furious.

There are degrees of madness as of folly.

1. Extreme folly; headstrong passion and rashness that act in opposition to reason; as the madness of a mob.

2. Wildness of passion; fury; rage; as the madness of despair.