INTELLIGENT › intelligent: Rachel's one of the smartest kids in the class.
TIDY › If you look smart or your clothes are smart, you look clean and tidy: a smart, blue suit I need to look a bit smarter for my interview.
FASHIONABLE › fashionable and expensive: a smart, new restaurant smart riverside apartments
MACHINE/WEAPON › A smart machine, weapon, etc uses computers to make it work: smart bombs
smartly adverb