Definition
A person may be judged according to his behaviour towards other people
How People Actually Use It
The last words someone hears when they mess with a Kingsman. Usually right before a bar fight in London. Your lesson: You hear Manners Maketh Man, you duck and fucking run (Who am I kidding? Chances are, if your fighting a Kingsman, your fucking dead already).
"News Story! In related news the suspect said the last words he heard before he was knocked out were "Manners Maketh Man", then he said a well-tailored guy who said the phrase hit him with a beer flying beer cup."
Source: Urban Dictionary