| Term | Definition | Contributor | Modified |
|---|---|---|---|
| Ophthalmometry | No definition provided | Christopher Rauch | 2023.12.01 |
| Ophthalmoscope and ophthalmoscopy | No definition provided | Christopher Rauch | 2023.12.01 |
| Opiates | No definition provided | Christopher Rauch | 2023.12.01 |
| Opik theory | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Opinion evidence | No definition provided | Christopher Rauch | 2023.12.01 |
| Opinion, Public | No definition provided | Christopher Rauch | 2023.12.01 |
| Opisthobranchiata | No definition provided | Christopher Rauch | 2023.12.01 |
| Opisthocomi | No definition provided | Christopher Rauch | 2023.12.01 |
| Opium | No definition provided | Christopher Rauch | 2023.12.01 |
| Opium habit | No definition provided | Christopher Rauch | 2023.12.01 |
| Opium, Physiological effect of | No definition provided | Christopher Rauch | 2023.12.01 |
| Opium--Toxicology | No definition provided | Christopher Rauch | 2023.12.01 |
| Opium trade | No definition provided | Christopher Rauch | 2023.12.01 |
| Opium war, 1840-1842. 5t’c’ China--Hist.--War of 1840-1842 | No definition provided | Christopher Rauch | 2023.12.01 |
| oplus | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Oporto, Portugal--Siege, 1832 | No definition provided | Christopher Rauch | 2023.12.01 |
| Opossums | No definition provided | Christopher Rauch | 2023.12.01 |
| Opossum-shrew | No definition provided | Christopher Rauch | 2023.12.01 |
| Opotherapy | No definition provided | Christopher Rauch | 2023.12.01 |
| Opportunity | No definition provided | Christopher Rauch | 2023.12.01 |