Definition
An irregular shaking or vibration of an aircraft structure caused by turbulent airflow striking it. Buffet is most commonly felt as the airflow over the wing begins to separate near the stall, but it can also occur from airflow off other surfaces such as flaps, spoilers, or the airframe at high Mach numbers.
Plain English
A shaking you feel through the airframe when disturbed air hits the airplane, often warning that the wing is getting close to a stall.
Context Anchor
Pilots usually notice buffet through the seat, control yoke or stick, or airframe during slow flight, steep turns, turbulence, or other conditions where airflow becomes rough.
Derivation
From the Old French 'buffet,' meaning a blow or a slap. The aircraft is being repeatedly 'slapped' by turbulent air, which captures the rapid, irregular nature of the shaking.
Why Pilots Care
It provides a natural, early warning of an approaching stall so the pilot can take action before losing lift.
Analogy
It is like driving over the rough edge of a road: the vibration is not the problem by itself, but it tells you something has changed and needs attention.
Grounding Statement
Buffet is felt, not just seen: the aircraft gives a physical shake when the air flowing over it becomes disturbed.
Intuition Check
Buffet does not mean a meal here, and it does not just mean any random bump. In aviation, buffet means shaking caused by disturbed airflow around the aircraft.
Example Sentence 1
As the airspeed bled off in the steep turn, the pilot felt a light buffet and immediately relaxed back pressure to lower the angle of attack.
Example Sentence 2
Recognizing the buffet, the pilot lowered the nose to restore smooth airflow.