Plain English Meaning
The written record that travels with an aircraft, showing what work has been done on it and what required checks have been completed. Pilots and mechanics both make entries in it, depending on what the regulations call for.
Full Definition
An official maintenance and operational record kept for an aircraft, in which required entries are made to document inspections, repairs, alterations, equipment checks, and other items mandated by regulation. Separate logbooks are typically maintained for the airframe, each engine, and each propeller.
Context Anchor
Seen when recording aircraft maintenance, inspections, and navigation-equipment checks, including a VOR receiver check made with a VOR facility.