Back-to-back and Headmost

Back-to-back adjective - Following one after another without others coming in between.

Headmost and back-to-back are semantically related. In some cases you can use "Headmost" instead an adjective phrase "Back-to-back".

Headmost adjective - Coming before all others in time or order.

Back-to-back and headmost are semantically related. Sometimes you can use "Back-to-back" instead an adjective "Headmost".