(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" (Ps 37:1, "Fret not thyself because of evil-doers"; Ps 37:7-8; Pr 24:19); of qatsaph, "to be angry," etc. (Isa 8:21, "They shall fret themselves, and curse," etc.); of raghaz, to be moved" (with anger, etc.) (Eze 16:43, "Thou hast fretted me in all these things," the American Standard Revised Version "raged against me"). For Le 13:55, see under Fretting below. (2) Intransitive, it is the translation of ra`am, "to rage," Hiphil, "to provoke to anger" (1Sa 1:6, "Her rival provoked her sore, to make her fret"); of za`aph, "to be sad," "to fret" (Pr 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" (Le 13:51-52; 14:44, "a fretting leprosy"; in Le 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" (Pr 21:19), margin "vexation."
W. L. Walker