(p. pr. & vb. n.) of Startle.

abrupt alarming amazing astonishing astounding awesome awing breathtaking chilling confounding daunting deterrent deterring disconcerting discouraging disheartening dismaying disquieting disturbing electrifying eye-opening fear-inspiring fearful fearsome frightening frightful hasty headlong impetuous impulsive jarring jolting mind-boggling nerve-shattering overawing overwhelming precipitant precipitate precipitous quick scaring scary shocking spectacular speedy staggering stunning sudden surprising swift terrifying unanticipated unexpected unforeseen unlooked-for unpredicted unsettling upsetting