A thrust reverser of a turbofan engine has a translating structure and a blocker door device capable of diverting a bypass flowpath for reversing propulsion direction. The translating structure moves axially between a forward position and a rearward position and thereby drives a compound motion of a blocker door of the blocker door device that moves between a respective stowed state and a deployed state. The compound motion is attributable through the blocker door being pivotally engaged to the translating structure, and through a multi-armed linkage of the device being pivotally engaged between a stationary structure, the blocker door and the translating structure. The linkage is further orientated such that it does not appreciably obstruct the bypass flowpath when the blocker door is in the stowed state.