(Noun)
Definition: a person who does something poorly ; a person who is not skillful at a job or other activity.
Source: http://www.merriam-webster.com/dictionary/amateur
From essay”who knows Brooklyn?”:” He’ an amateur…He never had an official position. No one ever appointed him.”
I believe Manbeck is not appreciated his competitor, it would be more likely to say Merlis is useless at his job, and did thing poorly.