Bottom line and Underlying

Bottom line noun - The central part or aspect of something under consideration.

Underlying and bottom line are semantically related. In some cases you can use "Underlying" instead an adjective phrase "Bottom line".

Underlying adjective - Of or relating to the simplest facts or theories of a subject.

Bottom line and underlying are semantically related. Sometimes you can replace phrase "Bottom line" with "Underlying", this terms are similar.