There are 11 words that start with 'penic'.
| penicil | penicils |
| penicillia | penicillin |
| penicillate | penicillins |
| penicillium | penicillamine |
| penicillinase | penicillamines |
| penicillinases | |
Note: These 11 words that start with 'penic' are found from the USA & Canada version of the tournament Scrabble word list.