Front line and Obverse

Front line noun - The leading or most important part of a movement.

Obverse and front line are semantically related. in forward topic. In some cases you can use "Obverse" instead a noun phrase "Front line".

Obverse noun - Something that is as different as possible from something else.

Front line and obverse are semantically related. Sometimes you can use "Front line" instead a noun "Obverse".