This is the 1525th most frequent Portuguese word.
fechar
To close.
Here 'fechar' is used in the literal sense of closing or shutting something, which in this case is a window.
Eu vou fechar a janela porque está frio.
I will close the window because it’s cold.
In this sentence, 'fechar' is used figuratively to mean finalizing or concluding an agreement or deal.
É melhor fechar o negócio enquanto temos uma boa oferta.
It’s better to close the deal while we have a good offer.
Here, 'fechar' refers to the act of concluding or ending an activity, which in this example is a presentation.