Bible Dictionary
FRET, FRETTING
To fret means to become angry, agitated, resentful, or troubled. It can also mean to eat away or corrode, as with a spreading disease or damaged fabric.
Biblical Usage
Scripture uses fret for anger toward evildoers, self-inflicted agitation, provocation, and resentment against the Lord. It also describes a fretting disease affecting garments or other material, including the leprosy mentioned in Leviticus.