| Proton | proton |
| Protonym | protonym |
| proto- | proto- |
| Photon | photon |
| Prokyon | Procyon |
| Propin | propyne |
| Protz | splurge boast |
| Protzen | splurge |
| protzen | show off splurge |
| Provo | Provo |
| Prolin | proline |
| Prolog | prologue prolog |
| Pronom | pronoun |
| Propan | propane |
| Propen | propene |
| Protein | protein |
| Proteom | proteome |
| Protze | limber |
| proben | rehearse |
| profan | mundane carnal profane secular |