What is the meaning of Thou art a flesh-monger a fool and a coward?

Chances are, the person who called you this is not very fond of you. The definition of monger is as follows: noun 1. a person who is involved with something in a petty or contemptible way (usually used in combination): a gossipmonger. By saying that you are a flesh monger the person is most likely trying to say that you are a person who is involved in stupid affairs. The definition of coward is as follows: -noun 1. a person who lacks courage in facing danger, difficulty, opposition, pain, etc.; a timid or easily intimidated person. (This definition pretty much speaks for itself)