***Meaning*** :: <u>G</u>round Lighting, <u>A</u>tmospheric Illusions, <u>R</u>unway Width, <u>R</u>unway/Terrain Sloping, <u>F</u>eatureless Terrain ***Source***: [[8 Acronyms Every Instrument Pilot Should Know]]^[Although they seem to have a typo, calling it GAARF instead.] #acronym