Definition of "RR"

(US) Initialism of railroad.  examples

(cycling) Initialism of road race.  examples

Abbreviation of rear, where brevity is desired.  examples

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.  examples

Initialism of Rolls-Royce.  examples

Initialism of reverse racism.  examples

Initialism of real reality.  examples

(statistics, epidemiology) Initialism of relative risk.

(US) Initialism of rural route used when addressing mail.  examples

Initialism of Riva-Roccin, a blood pressure measurer device  examples

Initialism of role reversal.  examples

(information technology) Initialism of resource record.

Abbreviation of Roraima, a state of Brazil.  examples

(aviation, travel, dated) (from the status code used in the GDS) reconfirm / reconfirmed.  examples