Synonyms for Dapper (same or very similar meaning)
WordNet sense 1 (marked by up-to-dateness in dress and manners):
dashing, jaunty, natty, raffish, rakish, snappy, spiffy, spruceWordNet sense 2 (being or in accordance with current social fashions):
fashionable, stylishFrom the ODE community, based on WordNetadd/edit