noun: (organic chemistry) Initialism of polychlorinated naphthalene. [(organic chemistry) Any of a range of compounds manufactured by treating naphthalene with chlorine; they have a variety of properties and uses.]
noun: (pharmacology) Abbreviation of penicillin. [(pharmacology) Any of a group of narrow-spectrum antibiotics obtained from Penicillium molds or synthesized, that have a beta-lactam structure and are active against gram-positive bacteria and used in the treatment of various infections and diseases.]
noun: (UK) Initialism of penalty charge notice: a notification of a fee for unauthorised parking of a vehicle
noun: (medicine) Initialism of primary care network.
