An expression said with emphasis and used to describe someone reacting (with or without reflex) with such grace and speed that it seems effortless. Anybody is capable of demonstrating The Quickness if their mind and reflexes are sharpened.
(2 men watching a video of a store owner disarming a robber with relative ease)
Man 1: "Dude, that was so smooth and fast, it's like he wasn't even trying!"
Man 2: "Bruh, The Quickness!"
(men laugh because they are stoned)
A phrase/suffix added at the end of sentences to imply the severe urgency of a situation. It can also be added to suggest the high speed of which an action is completed.
The house was on fire so Nate had to jump off the roof with the quickness.
Sandy was 30 minutes late for work, so she had to get dressed with the quickness.
Jason: DAAAAAYUM...You see that broad right there??
Keith: Yeah...she got cakes for days...
Jason: Yo, you need to scoop her up...with the quickness.