| Term | Definition |
| oss | bone |
| ostate | bone |
| ossify | to convert into or cause to harden like bone |
| ossicle | a small bone |
| osseous | composed of, containing, or resembling bone; bony |
| osteopath | a physician who practices osteopathy |
| osteology | the branch of anatomy dealing with the skeleton |
| ov | egg |
| ova | egg |
| oval | shape like circle, but longer than its wide |
| ovary | the part of an human female or female animal that produces egg |
| ovulate | when a women or female animal _____s, she produces egg inside body |
| oviparous | an _____ animal, fish, bird (etc.) produces eggs that develop and hatch outside its body |
| pec | peace |
| pacify | make someone calm, quiet and satisfied after they have been angry or upset |
| pacifist | someone who believes that all wars are wrong and who refuses to use violence |
| pacific | peaceful and loving peace |
| par | equal |
| parity | the state of being equal, esp. having equal pay, rights, or power |
| compare | to examine (two or more objects, ideas, people, etc.) in order to note similarities and differences |
| disparage | to speak of or treat slightingly; depreciate; belittle |
| disparate | distinct in kind; essentially different; dissimilar |
| par | an equality in value or standing; a level of equality |
| petr | rock |
| petroleum | an oily, thick, flammable, usually dark-colored liquid that is a form of bitumen or a mixture of various hydrocarbons |
| petrify | to convert into stone or a stony substance |
| peter | to diminish gradually and stop; dwindle to nothing, rock |