an international distress signal used by shore stations to inform a ship, aircraft, etc., of something vital to its safety or to the safety of one of its passengers.
Sometimes pan [pahn] /pɑn/.
Origin of pan-pan
reduplication and alteration of French panne ‘breakdown, failure’
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019