Semi-Independent Suspension
Semi-independent suspension lets the two wheels on an axle move relative to each other while retaining a structural connection that couples some of their motion.
Between independent and rigid
A torsion-beam rear axle is the common example: trailing arms carry the wheels and a connecting beam twists when the wheels move differently. The coupling is greater than in a fully independent layout but less rigid than a solid axle.
The category describes the connection, not a fixed level of comfort, grip, or roll stiffness. Beam shape, pivot locations, bushings, springs, dampers, tires, and body structure all affect the result.
For the construction categories and typical layouts, see Suspension Construction. The associated wheel paths and force coupling are explained in Suspension Kinematics and Vehicle Dynamics.