Far-off and Off the mark

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

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

Far-off and off the mark are semantically related in wide topic. Sometimes you can use "Far-off" instead an adjective phrase "Off the mark", if it concerns topics such as off-course.