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."
Source: Easton's Bible Dictionary
Madness
MAD'NESS, n. 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.
Source: King James Dictionary
Madness
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.