Synonyms and related words :
a corps perdu, abruptly, at half cock, bang, capriciously, chaotically, dash, erratically, every which way, hastily, head over heels, headfirst, headforemost, headlong, heels over head, helter-skelter, higgledy-piggledy, impetuously, in a rush, inconsistently, inconstantly, irregularly, like a flash, like a thunderbolt, nonuniformly, of a sudden, on short notice, overhastily, oversoon, plop, plump, plunk, pop, precipitantly, precipitately, precipitously, prematurely, quickly, rashly, recklessly, sharp, slap, slap-bang, smack, spasmodically, sporadically, startlingly, sudden, suddenly, surprisingly, too early, too soon, unawares, unequally, unevenly, unexpectedly, unsteadily, unsystematically, untimely, ununiformly, without notice, without warning