- (nautical) On the aft side; in the stern. [First attested in the early 17th century.]
"The mate sleeps abaft"
- (nautical, obsolete) Backwards. [Attested from around (1150 to 1350) until the late 15th century.]
"with the wind abaft"
- (nautical) Behind; toward the stern relative to some other object or position; aft of. [First attested around the late 15th century.]
"abaft the wheelhouse."