Noah Webster
Folly
FOL'LY, noun [See Fool.]
1. Weakness of intellect; imbecility of mind. want of understanding.
A fool layeth open his folly Proverbs 13:16.
2. A weak or absurd act not highly criminal; an act which is inconsistent with the dictates of reason, or with the ordinary rules of prudence. In this sense it may be used in the singular, but is generally in the plural. Hence we speak of the follies of youth.
3. An absurd act which is highly sinful; any conduct contrary to the laws of God or man; sin; scandalous crimes; that which violates moral precepts and dishonors the offender. Shechem wrought folly in Israel. Achan wrought folly in Israel. Genesis 34:7. Joshua 7:15.
4. Criminal weakness; depravity of mind.