Plain English Meaning
It is how quickly or slowly an instructor talks, and how they use pauses, so the student can actually take in what's being said.
Full Definition
In instructional communication, airspeed control refers to an instructor's deliberate management of how fast they speak, including the rate of words, the use of pauses, and variations in pace, so that a learner can absorb the information being delivered.
Context Anchor
You encounter airspeed control during almost every flight lesson, especially in climbs, descents, approaches, landings, and practice maneuvers.
Derivation
Airspeed combines air and speed: it is speed measured through the air, not speed across the ground. Control comes from the idea of directing or regulating something, which fits ’s job of setting and maintaining the needed speed.