Here are three ways to say tacky in Portuguese, meaning something with poor taste.
Ela comprou uma calça rosa. Que coisa brega! She bought a pair of pink pants. How tacky!
noun version: breguice [tackiness, tacky stuff]
Não acredito que a casa dele tem tanta breguice. I don’t believe his house has so much tacky stuff.
Acho meio cafona usar bota Ugg com saia. I think it’s kind of tacky to wear Ugg boots with a skirt.
noun version: cafonice [tackiness, tacky stuff]
O site mostra cafonices no mundo da moda. The site shows tacky stuff from the world of fashion.
3. deselegante (tacky, rude)
Ela foi para a festa de crianças usando um vestido super curto. Que deselegante! She went to the childrens’ party wearing a really short dress. How tacky!
You can also see how deselegante is used in this Globo news clip that went viral this year.