Blue-sky and Rum

Blue-sky adjective - Without immediate commercial value.

Rum and blue-sky are semantically related. In some cases you can use "Rum" instead an adjective phrase "Blue-sky".

Rum adjective - Different from the ordinary in a way that causes curiosity or suspicion.

Blue-sky and rum are semantically related. Sometimes you can use "Blue-sky" instead an adjective "Rum".