penicillin v potassium: a form of penicillin V (trade name Ledercillin VK)
penicillin v: a crystalline penicillin similar in action to penicillin G but more resistant to the action of gastric acids
plesiosaur: extinct marine reptile with a small head on a long neck a short tail and four paddle-shaped limbs; of the Jurassic and Cretaceous