the world > movement > rate of motion > swiftness > swift movement in specific manner > [adverb] > swiftly and suddenly (3)
With, or as with, a snap; quickly, smartly. Frequently in to go snap.
as adv. or int. expressing sudden movement or action. Obsolete slang or colloquial.
With a sudden spring or impetus; slap, smack. right spang, entirely, quite; exactly, fair.