For the acronym, see AFT (disambiguation).

Aft, in naval

Navy

A navy is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake- or ocean-borne combat operations and related functions...

 terminology

Terminology

Terminology is the study of terms and their use. Terms are words and compound words that in specific contexts are given specific meanings, meanings that may deviate from the meaning the same words have in other contexts and in everyday language. The discipline Terminology studies among other...

, is an adjective

Adjective

In grammar, an adjective is a 'describing' word; the main syntactic role of which is to qualify a noun or noun phrase, giving more information about the object signified....

 or adverb

Adverb

An adverb is a part of speech that modifies verbs or any part of speech other than a noun . Adverbs can modify verbs, adjectives , clauses, sentences, and other adverbs....

 meaning, towards the stern

Stern

The stern is the rear or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite of the bow, the foremost part of a ship. Originally, the term only referred to the aft port section...

 (rear) of the ship

Ship

Since the end of the age of sail a ship has been any large buoyant marine vessel. Ships are generally distinguished from boats based on size and cargo or passenger capacity. Ships are used on lakes, seas, and rivers for a variety of activities, such as the transport of people or goods, fishing,...

, when the frame of reference

Frame of reference

A frame of reference in physics, may refer to a coordinate system or set of axes within which to measure the position, orientation, and other properties of objects in it, or it may refer to an observational reference frame tied to the state of motion of an observer.It may also refer to both an...

 is within the ship. Example: "Able Seaman Smith; lay aft!". Or; "What's happening aft?"

• The corresponding adjective
  Adjective
  In grammar, an adjective is a 'describing' word; the main syntactic role of which is to qualify a noun or noun phrase, giving more information about the object signified....
  
  , in distinguishing one feature of the vessel from another is after. See the caption to the right. Its antonym is forward.
• The corresponding preposition is abaft. For example, the mizzenmast is abaft the mainmast. Its antonym
  Antonym
  In lexical semantics, opposites are words that lie in an inherently incompatible binary relationship as in the opposite pairs male : female, long : short, up : down, and precede : follow. The notion of incompatibility here refers to the fact that one word in an opposite pair entails that it is not...
  
   is before or, in a more clumsy form, forward of.

Aft also describes the direction of movement within an aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

; that is, towards the tail. Example: "Let's go aft." It may also describe the back/tail location or region within an aircraft cabin. Example: "Aft lavatory."

The difference of aft and stern is that aft is the inside (onboard) rearmost part of the vessel, while stern refers to the outside (offboard) rearmost part of the vessel.