R

R 1 Respiration. For example, a medical chart note of “R20” is shorthand for 20 respirations (breaths) per minute. 2 Right. A medical chart note of a burn on the “R digit 5” places the burn on the right little finger or toe. 3 Roentgen. 4 In chemistry, a radical. 5 On a prescription, recipe, which is Latin for “to take.” Also known as Rx.