Capricious

CAPRICIOUS means to be sudden, unpredictable or changing quickly/energetically. Usane Bolt is CAPRICIOUS when he takes off running, imagine standing next to him then BAM! he starts sprinting! that would scare the crap outta me. When someone scares you they are being CAPRICIOUS and when you scare someone you are being CAPRICIOUS. I suppose when something happens eg. someone falls ill and you saw them yesterday going for a run they would have turned ill CAPRICIOUSLY. Next time you are going for a run try being CAPRICIOUS.
                                                                                                                           Maddy x