Downhearted and Low-down

Downhearted adjective - Feeling unhappiness.

Low-down and downhearted are semantically related In some cases you can use "Low-down" instead an adjective "Downhearted".

Low-down adjective - Not following or in accordance with standards of honor and decency.

Downhearted and low-down are semantically related in depressed topic. Sometimes you can use "Downhearted" instead an adjective phrase "Low-down", if it concerns topics such as discouraged.