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."