Definition
A phrase used by ATC to inform a pilot that previously issued traffic is no longer a factor — meaning it will not affect the aircraft's flight path and no avoidance action is required.
Plain English
Controller is telling you the other aircraft they pointed out earlier is no longer a concern. You don't need to do anything about it.
Context Anchor
Heard on the radio after a controller has pointed out nearby traffic and then determines that specific aircraft is no longer a problem for you.
Derivation
Traffic comes from older words meaning movement or trade along a route. Factor comes from a Latin word meaning something that does or makes an effect. In this phrase, the traffic is no longer a factor because it is no longer expected to affect your flight.
Why Pilots Care
Allows the pilot to maintain focus on the primary task without making unneeded maneuvers that could create new conflicts.
Intuition Check
Do not read this as “there is no traffic anywhere nearby.” It means that the specific traffic previously called out is no longer expected to affect you.
Example Sentence 1
After the Cessna passed behind us, the controller called, 'Traffic no factor,' and I went back to my normal scan.
Example Sentence 2
After hearing 'traffic no factor,' the pilot continued the descent without altering heading.