Synonyms of sudden

1 Syllable
thest, swift, flash, fleet, quick, fast, rash, ther
2 Syllables
headlong, rushing, hastiest, abrupt, quickest, quicker, swiftest, hasty, fleeting, speeded, rapid, asap, speedball, theatric, swifter, hurried, hastier
3 Syllables
quickened, barrelling, double-quick, fleet-footed, dramatic, subito, impromptu, haphazard, asudden, impatient, spasmodic, fleetfooted, acute, impetuous, surprising, hot-and-cold, unusual, suddenly, unprompted
4 Syllables
unforbearing, histrionical, impulsive, unlooked-for, unpredicted, immediate, tragicomic, precipitous, precipitant, unknowingly, harefooted, unexpected, unforeseen, expeditious
5 Syllables
precipitate, accelerated, unmeditated
6 Syllables
unanticipated
7 Syllables
unanticipatedly