smarten up

verb4

1. •
   To wear smart clothes and look more stylish
2. •
   To make something look smart or smarter.

   • All the trains and the 300 stations were smartened up, "and we dared to advertise" - something that had previously been impossible because the offering was not good enough. — 2026
3. •
   To become less stupid or naive
4. •
   To make less stupid or naive