WordNet sense 1 (in accord with the most fashionable ideas or style):

up-to-date, cutting-edge

WordNet sense 2 (being or in accordance with current social fashions):

fashionable, stylish

WordNet sense 3 (having the shrewd resourcefulness needed to survive in an urban environment):

streetwise

WordNet sense 4 (showing mental alertness and calculation and resourcefulness):

smart