Plain English Meaning
The last day new information can be sent in to make it into the next update. Anything received after that day has to wait for the cycle after.
Full Definition
A published deadline before which navigation, obstacle, or procedure data must be received in order to be evaluated, processed, and incorporated into the next revision of an instrument flight procedure or aeronautical chart. Information that arrives after the cutoff is held over for a later revision cycle.
Context Anchor
Seen in discussions of instrument procedure chart updates, publication dates, and FAA revision cycles.
Derivation
From the everyday phrase 'to cut off,' meaning to stop something at a set point. In publishing and chart production, the cutoff is the moment the door closes on new submissions for the edition.