לָהַהּ lâhahh (H3856)

to be rabid (figuratively, insane); also (from the exhaustion of frenzy) to languish

1) (Qal) to languish, faint 2) to amaze, startle 2a) (Hithpalpel) madman (subst)

a primitive root meaning properly, to burn, i.e. (by implication)