Far-off and Unheard-of

Far-off adjective - Not close in time or space.

Unheard-of and far-off are semantically related. In some cases you can use "Unheard-of" instead an adjective phrase "Far-off".

Unheard-of adjective - Not known or experienced before.

Far-off and unheard-of are semantically related. Sometimes you can use "Far-off" instead an adjective phrase "Unheard-of".