Plain English Meaning
The planned go-around for an instrument approach. If the pilot reaches the point where they must see the runway and they cannot, or the landing is not safe for any reason, they fly the published escape route — climb, turn, and head to a holding point.
Full Definition
A maneuver flown by a pilot when an instrument approach cannot be completed to a landing. It follows a published procedure that specifies a climb, a heading or track, and a point or altitude at which to hold or receive further clearance. The missed approach begins at the missed approach point (MAP) or, on a precision approach, upon reaching or without the required , or any time a is not assured.