sudden Synonyms

abrupt impulsive unexpected unlooked-for precipitous impetuous whirlwind unceremonious unlooked unhoped-for unusual undreamt steeper subitaneous subito surprising swift swifter unawares undreamed unforeseen without warning unthought-of unpredicted unheralded unceremonially unanticipated unannounced unceremoniously unplanned on the spot out of the blue hotheaded unknowingly quickie unintentionally unexpectedly suddenness suddenly steep startling speedy ignorantly hurried headlong hasty fulminant fleet FAST explosive