Source : Webster's Revised Unabridged Dictionary (1913)

Aft \Aft\ ([.a]ft), adv. & a. [AS. [ae]ftan behind; orig.
   superl. of of, off. See {After}.] (Naut.)
   Near or towards the stern of a vessel; astern; abaft.

Source : WordNet®

aft
     adj : (nautical, aeronautical) situated at or toward the stern or
           tail [syn: {aft(a)}] [ant: {fore(a)}]

aft
     adv : 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" [syn: {abaft}, {astern}] [ant: {fore}]