Here, I will post "official" names & definitions of glitches & exploits in the game. If you have any questions, feel free to ask in the Human: Fall Fast Discord server!

Glitches:

Infinite Fly Glitch: A (currently patched) glitch where you jump infinitely in the air; usually would start happening when jumping on the conveyor belt at the end of Power. This is not the same as Item Hovering.

Spawn Displacement: A glitch where your character loads into a level with momentum rather than dropping straight down; this can occur when using a very old hard drive that causes loading to take longer than 10 seconds OR when you land on a physics object (such as the metal bar at the beginning of Power), exit the game and reload in quick succession to keep the rotational force from hitting the object.

Exploits:

Extended Climb (EC): When your character's feet are off the ground while grabbing a surface, and the character pulls themselves higher up and re-grabs the surface with specific timing to gain height.

Note: If your feet are on a surface they can jump from (i.e. the grass patch on Train), it is not an Extended Climb.

Swing Climb: When your character swings with one arm and re-grabs a surface with the other arm to gain height. This counts as a form of Extended Climbing.

Note: Swinging from side-to-side (i.e. to cross a gap) does not count as a Swing Climb.

Prop-Fly / Item Hover: Holding an item beneath your character and jumping off of it, whether you gain height or not. This is not the same as Infinite Fly Glitch.

Footsie: Clipping your leg on a precise spot (near checkpoint 2 on Water) so that your character touches the end zone right underneath the ground. Then if you die you beat the level.

There is something that people refer to as the "Glitch Grab" when Extended Climbing. This is actually programmed in; when your hand grabs anything, the game checks if the distance between your hand and hips is "too far". If it is too far, it forcibly disconnects the grab. This is why you will hear the grab sound at first, and then immediately lose the grab.

[Speedglitch] : It's a game state where you trick Human: Fall Flat's physics into thinking your character is falling. You now have the same properties as if you were falling. One of them being that you can accelerate infinitly.