Definition 1:
Person 1: Yo, did you hear that the R179s failed all their tests?
Person 2: Oof

Definition 2:
P1: Yo, I just bought this vacuum cleaner and it broke immediately.
P2: What an R179

Railfanner 1: Bro, I rarely or never seen any R42s on the J/Z? And saw some new cars that snoozes when it stops and it’s on the A/C including the J/Z? what are those?

All railfanners: A lemon. Aka the troublesome car named the R179.