Arched; concave; as, a vaulted roof.
Covered with an arch, or vault.
Arched like the roof of the mouth, as the upper lip of many ringent flowers.
An arched structure serving as roof, arched surface especially concave.
In this case, the award has an arched appearance instead of being flat. This was popular with the 1914 Iron Cross 1st Class, and some examples of the 1939 1st Class were constructed this way until this practice was banned in 1941.
an arched roof supported on pillars