Astern and Hindermost

Astern adverb - Near, toward, or in the stern of a ship or the tail of an aircraft.

Hindermost and astern are semantically related In some cases you can use "Hindermost" instead an adjective "Astern".

Hindermost adjective - Located farthest to the rear.

Astern and hindermost are semantically related in back topic. Sometimes you can use "Astern" instead an adjective "Hindermost".