a corps perdu abruptly bang carelessly dash desperately furiously happen what may hastily head over heels headfirst headforemost headlong heedlessly heels over head helter-skelter holus-bolus hotfoot hotheadedly hurriedly hurry-scurry impulsively like a flash like a thunderbolt like crazy like mad madly of a sudden on short notice overeagerly overenthusiastically overzealously plop plump plunk pop precipitantly precipitately precipitously quickly ramble-scramble rashly recklessly sharp slam-bang slap slap-bang slapdash smack startlingly sudden suddenly surprisingly unawares unexpectedly wantonly wildly without notice without warning