1. In a manner that is not suitable, appropriate, or correct; wrongly
The data was improperly stored, leading to corruption.
Os dados foram armazenados de forma imprópria, resultando em corrupção.
2. In a way that violates social norms, decorum, or propriety
He behaved improperly at the formal dinner.
Ele se comportou de forma imprópria no jantar formal.