Couth – Good manners, cultivated and refined
Cool youths (couth) can have pleasant manners, too.
Examples of couth in a sentence
Because she is couth and cultured, Mary knows the proper way to greet a member of the royal family.
The couth young man handled himself well at the formal dinner.
Despite having grown up in the country, Bridget is quite couth and knows her way around a wine cellar.