adverb (r)

• stern foremost or backward(adv.all)

  Example:
  The steamer went astern at half speed.
  

  source: wordnet30
• at or near or toward the stern of a ship or tail of an airplane(adv.all)

  Example:
  The captain looked astern to see what the fuss was about.
  

  Synonym:
  abaft, aft
  Antonym:
  fore, forward
  

  source: wordnet30
• (of a ship or an airplane) behind(adv.all)

  Example:
  We dropped her astern on the end of a seven-inch manilla, and she laid comfortably on the ebb tide.
  

  source: wordnet30
• In or at the hinder part of a ship; toward the hinder part, or stern; backward; as, to go astern.(adverb)

  source: webster1913