This is the 14352nd most frequent Russian word.
открыты
"Open."
Here, the word "открыты" is used as part of a past passive construction indicating that the windows were in an open state.
Окна были открыты, чтобы в комнату вошёл свежий воздух.
The windows were open to let fresh air into the room.
In this sentence, "открыты" describes a figurative state of mind, implying receptiveness.
Мы должны быть открыты к новым идеям и предложениям.
We should be open to new ideas and proposals.
This use of "открыты" indicates the current operational state of being open for business or visitors.