IFR

noun3

1. •
   Initialism of infection fatality rate.
2. •
   Initialism of instrument flight rules, a set of rules for a pilot flying on instruments, primarily as a means of navigating through inclement weather.
3. •
   (humorous) Initialism of I follow roads, to navigate simply via prominent ground features; this may be at very low level when flight would only normally be possible under Instrument Flight Rules.

   • Night flying is still a safe means of transportation, however, I have modified my VFR (Visual Flight Rules) night flights to a IFR (normally-Instrument Flight Rules) but in my case I Follow Roads[.] — 1980