| PEN | a form of penicillin V (trade name Ledercillin VK) |
|---|---|
| PEN | unaffected by penicillin |
| PEN | bacteria that are unaffected by penicillin |
| PEN | enzyme produced by certain bacteria that inactivates penicillin and results in resistance to that antibiotic |
| PEN | a form of penicillin that is not rendered inactive by penicillinase |
| PEN | genus of fungi commonly growing as green or blue molds on decaying food |
| PEN | of or relating to the penis |
| PEN | an implant that creates an artificial erection |
| PEN | a large mass of land projecting into a body of water |
| PEN | of or forming or resembling a peninsula |
| PEN | the male organ of copulation (`member' is a euphemism) |
| PEN | (psychoanalysis) a female's envy of the male's penis |