Fret, Fretting (charah, ma'ar):
To "fret" is from for (prefix) and etan, "to eat," "to consume." The word is both transitive and intransitive in King James Version:
(1) transitive as translation of charah, "to burn," Hithpael, "to fret one's self," "to be angry" (Psalms 37:1, "Fret not thyself because of evil-doers"; Psalms 37:7, Psalms 37:8, Proverbs 24:19); of qatsaph, "to be angry," etc. (Isaiah 8:21, "They shall fret themselves, and curse," etc.); of raghaz, to be moved" (with anger, etc.) (Ezekiel 16:43, "Thou hast fretted me in all these things," the American Standard Revised Version "raged against me"). For Leviticus 13:55, see under Fretting below.
(2) Intransitive, it is the translation of ra`am, "to rage," Hiphil, "to provoke to anger" (1 Samuel 1:6, "Her rival provoked her sore, to make her fret"); of za`aph, "to be sad," "to fret" (Proverbs 19:3, "His heart fretteth against Yahweh").
Fretting in the sense of eating away, consuming, is used of the leprosy, ma'ar, "to be sharp, bitter, painful" (Leviticus 13:51, Leviticus 13:52, Leviticus 14:44, "a fretting leprosy"; in Leviticus 13:55 we have "it (is) fret inward" ("fret" past participle), as the translation of pehetheth from pahath, "to dig" (a pit), the word meaning "a depression," "a hollow or sunken spot in a garment affected by a kind of leprosy," the Revised Version (British and American) "it is a fret."
Revised Version has "fretful" for "angry" (Proverbs 21:19), margin "vexation."
W. L. Walker