heruka (khrag 'thung). Literally, 'blood drinker.' A wrathful deity; drinker of the blood of ego-clinging.
"HE" is the cause or ground, dharmakaya, the future, and the emancipation of non-formation. "RU" is the place, disintegration, the path and thus it is the past, the emancipation of marklessness. "KA" is the particular, the fruition and thus it is the present, nirmanakaya and the emancipation of wishlessness. In another way, hela means "drinking" or "enjoying" (rol pa), rudhira means "blood" and kapala means "bliss sustainer" or "skull cup." Translated into Tibetan heruka means "enjoying/ drinking the blood of the skull" (thod pa'i khrag la rol pa). That is to say, having drunken the blood of the ego-clinging and disturbing emotions in one's own stream-of-being, the heruka is drinking the the blood of the ego-clinging and disturbing emotions in stream-of-being of other disciples. In short, heruka means blood-drinker (khrag 'thung). From Lamrim Yeshe Nyingpo.