From WordNet (r) 3.0 (2006): PRN adv 1: according to need (physicians use PRN in writing prescriptions); "add water as needed" [syn: as needed, as required, pro re nata, PRN]
PRN adv 1: according to need (physicians use PRN in writing prescriptions); "add water as needed" [syn: as needed, as required, pro re nata, PRN]
