At and Downhearted

At noun - A highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium.

Downhearted and at are semantically related. In some cases you can use "Downhearted" instead an adjective "At".

Downhearted adjective - Feeling unhappiness.

At and downhearted are semantically related. Sometimes you can use "At" instead an adjective "Downhearted".