Schild
Verteidigtes Gelände — was Sie schützen, und wovor.
A shield in a dream is the dictionary's image of defended ground. Unlike the sword, the shield does not advance; it holds. The dream often appears when you have been holding a position — a value, a boundary, a person — and the dream is acknowledging that you have been doing the work.
Where you often see it. A shield held in a defensive scene. A shield kept on a wall. The dream uses the shield for defended ground — what you have chosen to protect, and from what.
What it is not. A shield is not always combat. The dictionary reads it as deliberate defensive choice.
Related in the dictionary. Read shield with weapon (its companion), wall, castle, and any scene of chosen protection.