Plain English Meaning
Splitting your attention so you can keep doing several important things at once, instead of getting locked onto just one.
Full Definition
The skill of managing two or more flying tasks at the same time by shifting focus between them in a deliberate, controlled way — for example, scanning outside for traffic while also monitoring instruments and maintaining aircraft control.
Context Anchor
Used in flight training when an instructor introduces distractions or added tasks to help a learner keep control of the aircraft while managing more than one demand.
Derivation
From Latin 'dividere' meaning 'to separate or split.' In flying, the pilot is splitting their attention across multiple tasks rather than letting it fixed on one.