Probably from an unused root meaning to disintegrate; stupidity (as a result of grossness or of degeneracy) -- extremity.
H6580. pash
מַּשׁ noun [masculine] Job 35:15 si vera lectio from v פשׁשׁ (compare Arabic weak in mind or body, very stupid); — i.e. folly; but read מֶּשַׁל (ᵐ5 Theod ᵑ6 Di BaeKau Du).