This is the 4825th most frequent Portuguese word.
falso
False; fake.
Here, 'falso' is used as an adjective to describe the authenticity of the document, indicating it is not genuine or real.
O documento apresentado era falso.
The document presented was false.
In this context, 'falso' denotes insincerity, describing the smile as not being genuine but rather superficial.
Ele tinha um sorriso falso quando cumprimentou o chefe.
He had a fake smile when he greeted the boss.
Here, 'falso' is again an adjective describing the material as imitation or counterfeit, not real gold.