Definition of "Astern" :

adverb: (of a ship or an airplane) behind

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

adverb: at or near or toward the stern of a ship or tail of an airplane

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

adverb: stern foremost or backward

"The steamer went astern at half speed."