Mahā udakaṇṇavoti kho, bhikkhave, catunnetaṁ oghānaṁ adhivacanaṁ—

kāmoghassa, bhavoghassa, diṭṭhoghassa, avijjoghassa.  
‘Large deluge’ is a term for the four floods:

the floods of sensual pleasures, desire to be reborn, views, and ignorance.