Stabilizer Bar
Also called an "Anti-Roll Bar" "Anti-Sway Bar" or "Sway Bar."

A Stabilizer Bar is a bar linking the two front suspension systems in order to help them resist sway.

A suspension element (used at the front, rear or both ends of a vehicle) that reduces body roll by resisting any unequal vertical motion between the pair of wheels to which it is connected. A stabilizer bar does not affect suspension stiffness when both wheels are deflected equally in the same direction.