Flatten

[Sarah]

To lower the pitch of; to cause to sound less sharp; to letfall from the pitch. To flatten a sail (Naut.), to set it more nearlyfore-and-aft of the vessel.-- Flattening oven, in glass making, a heated chamber in which splitglass cylinders are flattened for window glass.

[Sarah]

to [crush] an object down from a greater size to a smaller one.
to make [roadkill] of a person while playing an FPS such as [halo] or [battlefield].

[Britney]

Make or become flat or flatter.

[Greta]

to become level or cause something to become level: