ASTERN

adv. (Nautical, Aeronautics) toward the back, toward the rear; backwards

Astern is the naval term for the back-end or rear of a vessel. "Astern" is synonymous with "aft", and the two words can be used interchangeably.
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Adverb
1. stern foremost or backward; "the steamer went astern at half speed"
2. at or near or toward the stern of a ship or tail of an airplane; "stow the luggage aft"; "ships with square sails sail fairly efficiently with the wind abaft"; "the captain looked astern to see what the fuss was about"
(synonym) aft, abaft
3. (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"
(classification) ship

n. aster, type of plant with large showy flowers; star-shaped structure formed in a cell (Biology)

(adv.)
In or at the hinder part of a ship; toward the hinder part, or stern; backward; as, to go astern.
  

(adv.)
Behind a ship; in the rear.