sudden Synonyms

abrupt precipitous unexpected unforeseen out of the blue hurried immediate unlooked-for impulsive instant prompt rapid quick suddenly instantaneous impetuous without warning surprising swift unpredicted startling unanticipated unplanned swifter subito undreamt undreamed unlooked whirlwind unawares unusual unhoped-for unceremonious unthought-of unprompted unheralded unceremonially unannounced unceremoniously explosive Out of nowhere on the spot hotheaded unknowingly quickie unintentionally unexpectedly suddenness subitaneous striking