Confines and Front line

Confines noun - A real or imaginary point beyond which a person or thing cannot go.

Front line and confines are semantically related. In some cases you can use "Front line" instead a noun "Confines".

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

Confines and front line are semantically related. Sometimes you can use "Confines" instead a noun phrase "Front line".