locked, reserved, closed-off
Falls Yu Arneson oder David irgendetwas sagen, bleibt dein Mund verschlossen.
If Yu Arneson or David says anything, keep your mouth shut.
They were locked.
He is very reserved.
The doors are locked.
This door is locked.
Tom bemerkte, dass die Tür nicht verschlossen war.
Tom noticed that the door was not locked.