coward
/ˈkauəd; `kaʊɚd/ n
(derog 贬) person who lacks courage; person who runs away from danger 胆小鬼; 懦夫
You miserable coward! 你这可怜的胆小鬼!
I'm a terrible coward when it comes to dealing with sick people, ie It scares me and I avoid it. 我一和病人打交道就提心吊胆.