Plain English Meaning

VA is the fastest speed at which you can yank a control fully in one direction without risking structural damage. Below this speed, the wing will give up (stall) before the airplane breaks. Above it, full or abrupt control inputs could bend or break something.

Full Definition

VA is the calibrated airspeed at or below which the airplane will stall before exceeding its certified limit load factor when full or abrupt control movement is applied on a single axis. It is established by the manufacturer during certification and may vary with aircraft weight. Operating at or below VA protects the airframe from structural overstress caused by sudden, full-deflection control inputs or sharp gusts, because the wing will stall and unload before the structure is overloaded.