| Term | Definition |
| Ornery | having an irritable disposition, cantankerous |
| Oscillate | to swing back and forth like a pendulum, to vary between opposing beliefs or feelings |
| Ossify | to change into bone; to become hardened or set in a rigidly conventional pattern |
| Ostracize | to exclude from a group by common consent |
| Oust | to remove from position by force; eject |
| Paean | a tribute, a song or expression of praise |
| Palatial | relating to a palace; magnificent |
| Palimpsest | an object or place having diverse layers or aspects beneath the surface |
| Palpable | capable of being touched or felt; easily perceived |
| Paltry | pitifully small or worthless |
| Panache | flamboyance or dash in style and action |
| Pandemic | occurring over a wide geographic area and affecting a large portion of the population |
| Panegyric | elaborate praise; formal hymn of praise |
| Paradigm | an outstandingly clear or typical example |
| Paragon | a model of excellence or perfection |