Final answer:
In the given context, disturbance refers to an interruption of the flow of air, which is critical in aerodynamics and the performance of aircraft parts. The correct answer is option 1.
Step-by-step explanation:
The definition of disturbance that most closely matches its use in the context of the provided excerpt is an interruption of flow. In this case, it refers to a disruption in the flow of air around airplane parts, which can affect the aircraft's performance. Air disturbance can be caused by a variety of factors, including uneven wing geometry or flawed designs that might disrupt the smooth flow of air.