First-line and Foremost

First-line adjective - Singled out from a number or group as more to one's liking.

Foremost and first-line are semantically related. In some cases you can use "Foremost" instead an adjective phrase "First-line".

Foremost adjective - Coming before all others in importance.

First-line and foremost are semantically related. Sometimes you can use "First-line" instead an adjective "Foremost".