1. RR - Noun
2. RR - Verb
3. RR - Proper noun
(US) Initialism of railroad.
(cycling) Initialism of road race.
Abbreviation of rear, where brevity is desired.
Initialism of right rear, a location in a square or rectangular layout such as the tires on an automobile or the heating elements on a stovetop.
Initialism of Rolls-Royce.
Initialism of reverse racism.
Initialism of real reality.
(statistics, epidemiology) Initialism of relative risk.
(US) Initialism of rural route used when addressing mail.
Initialism of Riva-Roccin, a blood pressure measurer device
RR
Abbreviation of Roraima, a state of Brazil.
RR
(aviation, travel, dated) (from the status code used in the GDS) reconfirm / reconfirmed.