It is a nautical term used primarily on ships. From memory I believe that it comes from arbitary settings of speed from Stop to Full Speed and any change of speed is communicated from the Bridge to the Engine Room.
Hence full speed ahead is a change to maximum speed on the ships present heading.
As fast as possible
The term 'full speed' is a compound noun made up of the adjective 'full' and the noun 'speed'.A noun adjunct is a noun functioning as an adjective, for example highway speed or city speed. The words 'highway' and 'city' are both nouns describing the noun 'speed'.The compound noun 'full speed' can function as a noun adjunct, for example, a full speed accident.
The nautical term is"Full steam ahead".
Drag . As in drag-parachute. Drag is also employed when a pilot engages the plane's flaps, while traveling pretty much at full speed, as an air brake to allow the pilot's target to get ahead.
If you go to full term the IUD will probably come out when the baby is delivered.
If the feces do not come out regularly as normal, the term is "impacted".
A term originally used by railroads. Before the use of automatic signals, a large ball on a string hung over the tracks was used. If it was low, the tracks ahead were possibly occupied and a low speed was supposed to be used. If the ball was raised high, the engineer could take the train to full speed because the track ahead was not occupied by another train. Out of use since the early 1900's or earlier in many places.
40 weeks is considered "full term" .
The term for increasing speed is accelerating.
Visibility.
The technical term for the speed of a river is velocity.
The African Luhya term for the English word 'ahead' is "imbelii".