| Term | Definition |
| putrescent | Undergoing decomposition of animal or vegetable matter accompanied by fetid odors. |
| pyre | A heap of combustibles arranged for burning a dead body. |
| pyromania | An insane propensity to set things on fire. |
| pyrotechnic | Pertaining to fireworks or their manufacture. |
| pyx | A vessel or casket, usually of precious metal, in which the host is preserved. |
| quackery | Charlatanry |
| quadrate | To divide into quarters. |
| quadruple | To multiply by four. |
| qualification | A requisite for an employment, position, right, or privilege. |
| qualify | To endow or furnish with requisite ability, character, knowledge, skill, or possessions. |
| qualm | A fit of nausea. |
| quandary | A puzzling predicament. |
| quantity | Magnitude. |
| quarantine | The enforced isolation of any person or place infected with contagious disease. |
| quarrelsome | Irascible. |
| quarter | One of four equal parts into which anything is or may be divided. |
| quarterly | Occurring or made at intervals of three months. |
| quartet | A composition for four voices or four instruments. |
| quarto | An eight-page newspaper of any size. |
| quay | A wharf or artificial landing-place on the shore of a harbor or projecting into it. |
| querulous | Habitually complaining. |
| query | To make inquiry. |
| queue | A file of persons waiting in order of their arrival, as for admittance. |
| quibble | An utterly trivial distinction or objection. |
| quiescence | Quiet. |
| quiescent | Being in a state of repose or inaction. |
| quiet | Making no noise. |
| quietus | A silencing, suppressing, or ending. |
| quintessence | The most essential part of anything. |
| quintet | Musical composition arranged for five voices or instruments. |
| quite | Fully. |
| Quixotic | Chivalrous or romantic to a ridiculous or extravagant degree. |
| rabid | Affected with rabies or hydrophobia. |
| racy | Exciting or exhilarating to the mind. |
| radiance | Brilliant or sparkling luster. |
| radiate | To extend in all directions, as from a source or focus. |
| radical | One who holds extreme views or advocates extreme measures. |
| radix | That from or on which something is developed. |
| raillery | Good-humored satire. |
| ramify | To divide or subdivide into branches or subdivisions. |
| ramose | Branch-like. |
| rampant | Growing, climbing, or running without check or restraint. |
| rampart | A bulwark or construction to oppose assault or hostile entry. |
| rancor | Malice. |
| rankle | To produce irritation or festering. |
| rapacious | Disposed to seize by violence or by unlawful or greedy methods. |
| rapid | Having great speed. |
| rapine | The act of seizing and carrying off property by superior force, as in war. |
| rapt | Enraptured. |
| raptorial | Seizing and devouring living prey. |