Literal translation
He knows the living of the world.
Meaning
he has good manners, knows how to behave
Explanation
This expression denotes good manners, that is, knowledge of proper etiquette and the ability to behave correctly in society. Viéure, used here as a noun derived from the verb to live, refers, in this use, to ways of living, the customs and conventions governing relations between people. Mounde, the world, refers less to the universe than to people, the society one moves within, its codes and expectations. Saup, to know, places this knowledge of proper conduct on the level of true expertise, acquired through observation and experience. The construction faithfully mirrors the equivalent French phrase savoir-vivre, with a word order emphasising the verb to know followed by its object, the living of the world. It is used in ordinary register to praise someone recognised for their social ease, able to behave with tact and propriety in any circumstance, in society as within the family.