Plain English Meaning
A short, sharp burst of wind that is noticeably stronger than the steady wind around it.
Full Definition
A sudden, brief increase in wind speed, generally defined by the National Weather Service as a peak wind speed of at least 16 knots with a variation of 10 knots or more between the peak and the lull. Gusts are reported in surface weather observations when these criteria are met.
Context Anchor
Seen in airport weather reports from automated weather systems, on ATIS, and during takeoff, landing, taxi, and approach planning.
Derivation
Gust comes from the Old Norse 'gustr,' meaning a blast of wind. The original sense — a sudden puff of moving — is exactly what the term still describes.