| oxeye daisy |
a daisy that has a bright yellow center with white petals around it. |
| oxford |
a sturdy, plain shoe that laces over the top of the foot. |
| oxide |
a compound that includes oxygen. |
| oxidize |
to combine with oxygen. [2 definitions] |
| oxygen |
Oxygen is a gas that is a part of air. Oxygen has no color or smell, and we can't see it. When we breathe, our bodies take in oxygen from the air. Without oxygen, we cannot live. Other living things need oxygen too. |
| oyster |
An oyster is a small animal with a soft body and a hard shell that has two parts that can open and close. Oyster shells are very shiny inside, and sometimes pearls grow in them. Oysters live in shallow parts of the ocean. |
| oz. |
abbreviation of "ounce" or "ounces." |
| ozone |
a form of oxygen that occurs when oxygen is exposed to an electrical charge, like lightning. It is found naturally in Earth's atmosphere. |
| ozone hole |
an area in the ozone layer where the ozone becomes thin. There is a large ozone hole over Antarctica and a smaller one over the North Pole. Scientists warn us this is dangerous. |
| ozone layer |
an atmospheric layer between ten and twenty miles above the earth that contains a large amount of ozone, which absorbs certain types of harmful radiation from space. |
| P2 |
symbol of the chemical element phosphorus. |
| p |
the sixteenth letter of the English alphabet. [2 definitions] |
| p. |
abbreviation of "page." |
| PA1 |
abbreviation of "Pennsylvania." |
| pace1 |
The pace of something is how fast it moves. [5 definitions] |
| pacemaker |
a small electronic device put under the skin to control the heart rate in people with heart problems. |
| Pacific |
the largest ocean in the world. It lies between North America and Asia in the north, and South America and Australia in the south; Pacific Ocean. |
| Pacific Ocean |
The Pacific Ocean is one of five oceans of the world. An ocean is a large body of salt water that covers a very large part of the earth. The Pacific Ocean is the largest and the deepest of the world's oceans. If you are on a beach in California looking out at the ocean, the ocean you are looking at is the Pacific Ocean. |
| pacify |
to calm or bring back peace of mind to. |
| -pack |
a suffix that means a package containing that number of items. |
| pack1 |
A pack is a group of things arranged together in a container, or it is the container that the things are put into. A pack is a package. [13 definitions] |