• (America) IPA: /əˈstɝn/
• (RP) IPA: /əˈstɜːn/

astern (nautical)

1. Behind (a vessel); in the rear.
   • 1719 April 24, [Daniel Defoe], The Life and Strange Surprizing Adventures of Robinson Crusoe, […], London: Printed by W[illiam] Taylor […], OCLC 15864594 ↗; 3rd edition, London: Printed by W[illiam] Taylor […], 1719, OCLC 838630407 ↗, page 50 ↗:

     After we had row'd, or rather driven about a League and a Half, as we reckon'd it, a raging Wave, Mountain-like, came rowling a-stern of us, and plainly bad us expect the Coup-de-Grace.

2. In the direction of the stern; backward (motion); to the rear.
3. (obsolete or rare) At or toward the rear of a vessel.

• ahead

• German: achtern
• Spanish: hacia atrás

astern (not comparable) (nautical)

1. Behind a vessel; having a bearing of 180 degrees from ahead.

   If one ship is following another, the first is astern of the second.

• German: achterlich
• Spanish: detrás, a popa