acceleration 

Defined as the change in velocity over a period of time. Acceleration is a vector quantity and therefore is stated as a quantity with a direction.

a = (v-u)/t (where a, v and u are vectors)

Where (using SI units):
a = acceleration of the body in metres per second per second (ms^-2, or metres per second squared)
v = final velocity of the body in metres per second (ms^-1)
u = initial velocity of the body in metres per second (ms^-1)
t = time period between the initial and final velocity, in seconds (s)

An accelerating body can also be decelerating (ie, negative acceleration) or be at rest. Also, instantaneous acceleration is a bit different.

1) A car that is travelling at 2ms^-1 changes its speed to 6ms^-1 over a period of five seconds, and doesn't change direction. During that five seconds, it had an average acceleration of .8ms^-2 in initial direction.

2) A car travelling forwards at 2ms^-1 is suddenly put into reverse and five seconds later it is travelling 2ms^-2 backwards. It's average acceleration is .8ms^-2 backwards (-.8ms^-2 forwards). Note in this example, the car would have been temporarily at rest just when it changes direction. It is still accelerating (in negative direction, ie backwards, ie decelerating) during this period.

acceleration by White Razor December 24, 2008

Acceleration 

The process of getting high on speed

Yeah baby! I'm getting mad acceleration on this shit!

Acceleration by Brovahkiin93 June 2, 2016

acceleration 

the rate of change of velocity per unit of time.

a car accelerating from rest experiences a change in velocity over a specific time interval, meaning it has a positive acceleration.

acceleration by Arminkshipper August 16, 2025

acceleration marks 

Acceleration marks are crap stains that you intentionally leave in your underwear. They are in essence, the opposite of skid marks, and are so named accordingly.

All that chilli I ate yesterday has let me do some sweet acceleration marks in my shorts. Just a little scratching is all it takes.

acceleration marks by the nesto December 23, 2007

acceleration.don 

litterally so epic. the coolest system ever ugh.

"hey r u acceleration.don?"
"no"
"ew."

acceleration.don by heybestieykwhoiam July 12, 2021

acceleration.don 

a very cool and pretty person who makes tiktoks and is a top top editor

in example, acceleration.don is very pretty

acceleration.don by hwoneyzdadog July 12, 2021

premature acceleration 

When the person behind you in traffic changes lanes and accelerates to pass only to find that there is not enough room and they have to get back in line.

Driver: Did you see that guy try to pass me? He had to slow down and get back in line.
Passenger: Yeah, that was a case of premature acceleration.

premature acceleration by Morgore December 18, 2008