Be hopping mad

I think it could be either:
'be hopping mad' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for boil that I've seen before include "Painful sore" , "Sore with a hard core filled with pus" , "let off steam" , "Abscess" , "Cook, swelling" .)
(Other definitions for leap that I've seen before include "Jump, spring" , "vault" , "Jump across" , "Spring suddenly" , "Sudden bound" .)