What is "upsprung"

Usage examples of "upsprung".

V Now sleeping once on a day of marvellous fire, A brood of snakes he had cherished in grave regret That death his people had dealt their dam and their sire, Through savage dread of them, crept to his neck, and set Their tongues to lick him: the swift affectionate tongue Of each ran licking the slumberer: then his ears A forked red tongue tickled shrewdly: sudden upsprung, He heard a voice piping: Ay, for he has no fears!