nebbish       
 noun [ C ] US informal disapproving uk/ˈneb.ɪʃ/ us/ˈneb.ɪʃ/
 无能的人,胆小怕事的人,不自信的人
a person who is considered to be weak and lacking in confidence or courage
  A nebbish could never gain real power. 弱者永远无法获得真正的权力。 
 Sandler reprises once again his clueless, well-meaning nebbish who wants to be liked. 桑德勒再次塑造了一个既无知又无能的老好人的形象。 
 - More examples
 - Mr. Allen's typical alter egos are variations of the neurotic nebbish he has so often played.
 - I mean, he talks like such a nebbish, right?
 - The comic is about the daily travails of a put-upon teenage nebbish.
 
nebbish       
adjective US informal disapproving uk/ˈneb.ɪʃ/ us/ˈneb.ɪʃ/
 无能的,胆小怕事的,不自信的
considered to be weak and lacking in confidence or courage
  He is a nebbish but wealthy New York lawyer. 他是一位平庸却富有的纽约律师。 
 He wanted to prove that he was a character actor, not just some nebbish kid. 他想证明自己是一个角色演员,而不仅仅是个演技平平的毛头小子。 
 - More examples
 - Francis ends up in his nebbish brother's care.
 - The nebbish director has had a run of mediocre flops for some years now, disappointing his fans.
 - Jack Lemmon is superb as the nebbish insurance clerk whose apartment is used by philandering executives .